diff --git a/Sources/EstimatedPressureDependency/Key.swift b/Sources/EstimatedPressureDependency/Key.swift
index c9746d4..fe4d256 100644
--- a/Sources/EstimatedPressureDependency/Key.swift
+++ b/Sources/EstimatedPressureDependency/Key.swift
@@ -66,15 +66,15 @@ public struct EstimatedPressureDependency {
 
 extension EstimatedPressureDependency {
   private func estimatedPressure(
-    existingPressure: Positive<Double?>,
-    existingAirflow: Double,
-    targetAirflow: Double
+    existingPressure: Positive<Double>,
+    existingAirflow: Positive<Double>,
+    targetAirflow: Positive<Double>
   ) async throws -> Positive<Double> {
     try await self.estimatedPressure(
       .init(
-        existingPressure: existingPressure.positiveValue ?? 0,
-        existingAirflow: existingAirflow,
-        targetAirflow: targetAirflow
+        existingPressure: existingPressure.positiveValue,
+        existingAirflow: existingAirflow.positiveValue,
+        targetAirflow: targetAirflow.positiveValue
       )
     )
   }
@@ -83,78 +83,75 @@ extension EstimatedPressureDependency {
     equipmentMeasurement: EquipmentMeasurement,
     airflow updatedAirflow: Double
   ) async throws -> EquipmentMeasurement {
+    let updatedAirflow = Positive(updatedAirflow)
+
     switch equipmentMeasurement {
     case let .airHandler(airHandler):
-      guard let existingAirflow = airHandler.airflow else {
-        throw InvalidAirflow()
-      }
       return try await .airHandler(
         .init(
           airflow: updatedAirflow,
+          manufacturersIncludedFilterPressureDrop: airHandler.$manufacturersIncludedFilterPressureDrop,
           returnPlenumPressure: self.estimatedPressure(
             existingPressure: airHandler.$returnPlenumPressure,
-            existingAirflow: existingAirflow,
+            existingAirflow: airHandler.$airflow,
             targetAirflow: updatedAirflow
           ),
           postFilterPressure: self.estimatedPressure(
             existingPressure: airHandler.$postFilterPressure,
-            existingAirflow: existingAirflow,
+            existingAirflow: airHandler.$airflow,
             targetAirflow: updatedAirflow
           ),
           postCoilPressure: self.estimatedPressure(
             existingPressure: airHandler.$postCoilPressure,
-            existingAirflow: existingAirflow,
+            existingAirflow: airHandler.$airflow,
             targetAirflow: updatedAirflow
           ),
           supplyPlenumPressure: self.estimatedPressure(
             existingPressure: airHandler.$supplyPlenumPressure,
-            existingAirflow: existingAirflow,
+            existingAirflow: airHandler.$airflow,
             targetAirflow: updatedAirflow
           )
         )
       )
 
     case let .furnaceAndCoil(furnaceAndCoil):
-      guard let existingAirflow = furnaceAndCoil.airflow else {
-        throw InvalidAirflow()
-      }
       return try await .furnaceAndCoil(
         .init(
           airflow: updatedAirflow,
+          manufacturersIncludedFilterPressureDrop: furnaceAndCoil.$manufacturersIncludedFilterPressureDrop,
           returnPlenumPressure: self.estimatedPressure(
             existingPressure: furnaceAndCoil.$returnPlenumPressure,
-            existingAirflow: existingAirflow,
+            existingAirflow: furnaceAndCoil.$airflow,
             targetAirflow: updatedAirflow
           ),
           postFilterPressure: self.estimatedPressure(
             existingPressure: furnaceAndCoil.$postFilterPressure,
-            existingAirflow: existingAirflow,
+            existingAirflow: furnaceAndCoil.$airflow,
             targetAirflow: updatedAirflow
           ),
           preCoilPressure: self.estimatedPressure(
             existingPressure: furnaceAndCoil.$preCoilPressure,
-            existingAirflow: existingAirflow,
+            existingAirflow: furnaceAndCoil.$airflow,
             targetAirflow: updatedAirflow
           ),
           supplyPlenumPressure: self.estimatedPressure(
             existingPressure: furnaceAndCoil.$supplyPlenumPressure,
-            existingAirflow: existingAirflow,
+            existingAirflow: furnaceAndCoil.$airflow,
             targetAirflow: updatedAirflow
           )
         )
       )
-
     }
   }
 
   public func estimatedPressure(
     equipmentMeasurement: EquipmentMeasurement,
-    airflow updatedAirflow: Double,
+    airflow updatedAirflow: Positive<Double>,
     filterPressureDrop: Positive<Double>
   ) async throws -> EquipmentMeasurement {
     let estimate = try await estimatedPressure(
       equipmentMeasurement: equipmentMeasurement,
-      airflow: updatedAirflow
+      airflow: updatedAirflow.positiveValue
     )
 
     switch estimate {
@@ -183,7 +180,7 @@ extension EstimatedPressureDependency {
     return try await estimatedPressure(
       equipmentMeasurement: equipmentMeasurement,
       airflow: updatedAirflow,
-      filterPressureDrop: filterPressureDrop
+      filterPressureDrop: Positive(filterPressureDrop.positiveValue)
     )
   }
 }
@@ -219,42 +216,6 @@ extension EstimatedPressureDependency: DependencyKey {
   }
 }
 
-fileprivate extension EquipmentMeasurement.AirHandler {
-  init(
-    airflow: Double? = nil,
-    returnPlenumPressure: Positive<Double>,
-    postFilterPressure: Positive<Double>,
-    postCoilPressure: Positive<Double>,
-    supplyPlenumPressure: Positive<Double>
-  ) {
-    self.init(
-      airflow: airflow,
-      returnPlenumPressure: returnPlenumPressure.positiveValue,
-      postFilterPressure: postFilterPressure.positiveValue,
-      postCoilPressure: postCoilPressure.positiveValue,
-      supplyPlenumPressure: supplyPlenumPressure.positiveValue
-    )
-  }
-}
-
-fileprivate extension EquipmentMeasurement.FurnaceAndCoil {
-  init(
-    airflow: Double? = nil,
-    returnPlenumPressure: Positive<Double>,
-    postFilterPressure: Positive<Double>,
-    preCoilPressure: Positive<Double>,
-    supplyPlenumPressure: Positive<Double>
-  ) {
-    self.init(
-      airflow: airflow,
-      returnPlenumPressure: returnPlenumPressure.positiveValue,
-      postFilterPressure: postFilterPressure.positiveValue,
-      preCoilPressure: preCoilPressure.positiveValue,
-      supplyPlenumPressure: supplyPlenumPressure.positiveValue
-    )
-  }
-}
-
 struct InvalidAirflow: Error { }
 
 enum LessThanZeroError: Error {
diff --git a/Sources/FlaggedViews/FlaggedEquipmentMeasurementView.swift b/Sources/FlaggedViews/FlaggedEquipmentMeasurementView.swift
index b8abd9b..122594d 100644
--- a/Sources/FlaggedViews/FlaggedEquipmentMeasurementView.swift
+++ b/Sources/FlaggedViews/FlaggedEquipmentMeasurementView.swift
@@ -145,6 +145,7 @@ fileprivate extension EquipmentMeasurement.FlaggedMeasurement {
 #if DEBUG
 private let equipmentMeasurement = EquipmentMeasurement.airHandler(.init(
   airflow: 1600,
+  manufacturersIncludedFilterPressureDrop: 0.1,
   returnPlenumPressure: 0.37,
   postFilterPressure: 0.78,
   postCoilPressure: 0.9,
diff --git a/Sources/PressureEstimationsFeature/EquipmentMeasurementForm.swift b/Sources/PressureEstimationsFeature/EquipmentMeasurementForm.swift
index 68ae453..845ed36 100644
--- a/Sources/PressureEstimationsFeature/EquipmentMeasurementForm.swift
+++ b/Sources/PressureEstimationsFeature/EquipmentMeasurementForm.swift
@@ -1,9 +1,9 @@
 import ComposableArchitecture
+import DependenciesAdditions
 import SharedModels
 import Styleguide
 import SwiftUI
 
-
 @Reducer
 public struct EquipmentMeasurementForm {
   
@@ -11,12 +11,14 @@ public struct EquipmentMeasurementForm {
   
   @Reducer(state: .equatable)
   public enum Destination {
+    case flaggedMeasurementsList(FlaggedMeasurementsList)
     case infoView(InfoViewFeature)
   }
   
   @ObservableState
   public struct State: Equatable {
     @Presents public var destination: Destination.State?
+    @Shared public var sharedSettings: SharedPressureEstimationSettings
     public var allowEquipmentTypeSelection: Bool
     public var equipmentType: EquipmentMeasurement.EquipmentType
     public var focusedField: Field?
@@ -25,12 +27,14 @@ public struct EquipmentMeasurementForm {
     public init(
       allowEquipmentTypeSelection: Bool = true,
       destination: Destination.State? = nil,
+      sharedSettings: Shared<SharedPressureEstimationSettings>,
       equipmentType: EquipmentMeasurement.EquipmentType = .airHandler,
       focusedField: Field? = nil,
       measurements: Measurements = .init()
     ) {
       self.allowEquipmentTypeSelection = allowEquipmentTypeSelection
       self.destination = destination
+      self._sharedSettings = sharedSettings
       self.equipmentType = equipmentType
       self.focusedField = focusedField
       self.measurements = measurements
@@ -39,14 +43,27 @@ public struct EquipmentMeasurementForm {
     public var equipmentMeasurement: EquipmentMeasurement {
       measurements.equipmentMeasurement(type: equipmentType)
     }
-    
-    public var isValid: Bool {
-      measurements.airflow != nil
+
+    private var baseValidations: Bool {
+      return measurements.airflow != nil
       && measurements.returnPlenumPressure != nil
-      && measurements.postFilterPressure != nil
-      && measurements.coilPressure != nil
       && measurements.supplyPlenumPressure != nil
     }
+
+    private var furnaceAndCoilValidations: Bool {
+      return measurements.postFilterPressure != nil
+      && measurements.coilPressure != nil
+      && baseValidations
+    }
+
+    public var isValid: Bool {
+      switch equipmentType {
+      case .airHandler:
+        return baseValidations
+      case .furnaceAndCoil:
+        return furnaceAndCoilValidations
+      }
+    }
     
     public struct Measurements: Equatable {
       public var airflow: Double?
@@ -96,23 +113,24 @@ public struct EquipmentMeasurementForm {
         type: EquipmentMeasurement.EquipmentType
       ) -> EquipmentMeasurement {
         switch type {
-          
         case .airHandler:
           return .airHandler(.init(
-            airflow: airflow,
-            returnPlenumPressure: returnPlenumPressure,
-            postFilterPressure: postFilterPressure,
-            postCoilPressure: coilPressure,
-            supplyPlenumPressure: supplyPlenumPressure
+            airflow: airflow ?? 0,
+            manufacturersIncludedFilterPressureDrop: 0.1,
+            returnPlenumPressure: returnPlenumPressure ?? 0,
+            postFilterPressure: postFilterPressure ?? 0,
+            postCoilPressure: coilPressure ?? 0,
+            supplyPlenumPressure: supplyPlenumPressure ?? 0
           ))
           
         case .furnaceAndCoil:
           return .furnaceAndCoil(.init(
-            airflow: airflow,
-            returnPlenumPressure: returnPlenumPressure,
-            postFilterPressure: postFilterPressure,
-            preCoilPressure: coilPressure,
-            supplyPlenumPressure: supplyPlenumPressure
+            airflow: airflow ?? 0,
+            manufacturersIncludedFilterPressureDrop: 0,
+            returnPlenumPressure: returnPlenumPressure ?? 0,
+            postFilterPressure: postFilterPressure ?? 0,
+            preCoilPressure: coilPressure ?? 0,
+            supplyPlenumPressure: supplyPlenumPressure ?? 0
           ))
         }
       }
@@ -138,11 +156,15 @@ public struct EquipmentMeasurementForm {
     @CasePathable
     public enum View {
       case infoButtonTapped
+      case nextButtonTapped
+      case onAppear
       case resetButtonTapped
       case submitField
     }
   }
-  
+
+  @Dependency(\.logger["\(Self.self)"]) var logger
+
   public var body: some Reducer<State, Action> {
     BindingReducer()
     Reduce<State, Action> { state, action in
@@ -160,12 +182,37 @@ public struct EquipmentMeasurementForm {
         case .infoButtonTapped:
           state.destination = .infoView(.init())
           return .none
-          
+
+        case .nextButtonTapped:
+          guard state.isValid else {
+            return .fail(
+              """
+              Received next button tapped action, but the state is not valid.
+
+              This is considered an application logic error.
+              """,
+              logger: logger
+            )
+          }
+          state.sharedSettings.equipmentMeasurement = state.equipmentMeasurement
+          state.destination = .flaggedMeasurementsList(.init(sharedSettings: state.$sharedSettings))
+          return .none
+
+        case .onAppear:
+          guard let measurement = state.sharedSettings.equipmentMeasurement else {
+            return .none
+          }
+          state.measurements = .init(equipmentMeasurement: measurement)
+          return .none
+
         case .resetButtonTapped:
           state.measurements = .init()
           return .none
-          
+
         case .submitField:
+          if state.focusedField == .airflow {
+            return .send(.view(.nextButtonTapped))
+          }
           state.focusedField = state.focusedField?.next
           return .none
           
@@ -183,6 +230,12 @@ extension Store where State == EquipmentMeasurementForm.State {
   ) -> String {
     let label = label(field: field)
     guard field != .airflow else { return label }
+    if field == .coilPressure && state.equipmentType == .airHandler {
+      return "\(label) (Optional)"
+    }
+    if field == .postFilterPressure && state.equipmentType == .airHandler {
+      return "\(label) (Optional)"
+    }
     return "\(label) Pressure"
   }
   
@@ -269,8 +322,14 @@ public struct EquipmentMeasurementFormView: View {
         }
       }
     }
+    .onAppear { send(.onAppear) }
     .textLabelStyle(.boldSecondary)
     .textFieldStyle(.roundedBorder)
+    .toolbar {
+      NextButton { send(.nextButtonTapped) }
+        .nextButtonStyle(.toolbar)
+        .disabled(!store.isValid)
+    }
     .sheet(
       item: $store.scope(state: \.destination?.infoView, action: \.destination.infoView)
     ){ store in
@@ -278,6 +337,14 @@ public struct EquipmentMeasurementFormView: View {
         InfoView(store: store)
       }
     }
+    .navigationDestination(
+      item: $store.scope(
+        state: \.destination?.flaggedMeasurementsList,
+        action: \.destination.flaggedMeasurementsList
+      )
+    ) { store in
+      FlaggedMeasurementListView(store: store)
+    }
   }
   
   private func textField(
@@ -350,7 +417,9 @@ fileprivate extension InfoViewFeature.State {
 #Preview {
   NavigationStack {
     EquipmentMeasurementFormView(
-      store: Store(initialState: EquipmentMeasurementForm.State()) {
+      store: Store(initialState: EquipmentMeasurementForm.State(
+        sharedSettings: Shared(SharedPressureEstimationSettings()))
+      ) {
         EquipmentMeasurementForm()
       }
     )
diff --git a/Sources/PressureEstimationsFeature/EquipmentSettingsForm.swift b/Sources/PressureEstimationsFeature/EquipmentSettingsForm.swift
index 4f45778..8e78e01 100644
--- a/Sources/PressureEstimationsFeature/EquipmentSettingsForm.swift
+++ b/Sources/PressureEstimationsFeature/EquipmentSettingsForm.swift
@@ -4,13 +4,13 @@ import SharedModels
 import Styleguide
 import SwiftUI
 
-
 @Reducer
 public struct EquipmentSettingsForm {
 
   @CasePathable
   public enum InfoView {
     case capacities
+    case manufacturersIncludedFilterPressureDrop
     case ratedStaticPressures
   }
 
@@ -21,34 +21,27 @@ public struct EquipmentSettingsForm {
 
   @ObservableState
   public struct State: Equatable {
-
     @Presents public var destination: Destination.State?
-    public var coolingCapacity: EquipmentMetadata.CoolingCapacity
+    public var includesFilterDrop: Bool
     public var equipmentType: EquipmentMeasurement.EquipmentType
-    public var fanType: EquipmentMetadata.FanType
     public var focusedField: Field? = nil
-    public var heatingCapacity: Double?
-    public var ratedStaticPressures: RatedStaticPressures
+    @Shared public var sharedSettings: SharedPressureEstimationSettings
 
     public init(
-      coolingCapacity: EquipmentMetadata.CoolingCapacity = .default,
       destination: Destination.State? = nil,
+      includesFilterDrop: Bool = false,
       equipmentType: EquipmentMeasurement.EquipmentType = .airHandler,
-      fanType: EquipmentMetadata.FanType = .constantSpeed,
-      heatingCapacity: Double? = nil,
-      ratedStaticPressures: RatedStaticPressures = .init()
+      sharedSettings: Shared<SharedPressureEstimationSettings>
     ) {
-      self.coolingCapacity = coolingCapacity
       self.destination = destination
+      self.includesFilterDrop = includesFilterDrop
       self.equipmentType = equipmentType
-      self.fanType = fanType
-      self.heatingCapacity = heatingCapacity
-      self.ratedStaticPressures = ratedStaticPressures
+      self._sharedSettings = sharedSettings
     }
 
     public var isValid: Bool {
       guard equipmentType == .furnaceAndCoil else { return true }
-      return heatingCapacity != nil
+      return sharedSettings.heatingCapacity != nil
     }
 
     // Note: These need to be in display order.
@@ -57,6 +50,7 @@ public struct EquipmentSettingsForm {
       case minimumStaticPressure
       case maximumStaticPressure
       case ratedStaticPressure
+      case manufacturersIncludedFilterPressureDrop
     }
   }
 
@@ -68,7 +62,6 @@ public struct EquipmentSettingsForm {
     @CasePathable
     public enum View {
       case infoButtonTapped(InfoView)
-      case nextButtonTapped
       case resetButtonTapped
       case submitField
     }
@@ -79,6 +72,17 @@ public struct EquipmentSettingsForm {
     Reduce<State, Action> { state, action in
       switch action {
 
+      case .binding(\.includesFilterDrop):
+        guard state.includesFilterDrop else {
+          state.sharedSettings.manufacturersIncludedFilterPressureDrop = nil
+          return .none
+        }
+        guard state.sharedSettings.manufacturersIncludedFilterPressureDrop != nil else {
+          return .none
+        }
+        state.sharedSettings.manufacturersIncludedFilterPressureDrop = 0.1
+        return .none
+
       case .binding:
         return .none
 
@@ -96,12 +100,8 @@ public struct EquipmentSettingsForm {
           state.destination = .infoView(.init(view: infoView))
           return .none
 
-        case .nextButtonTapped:
-          #warning("Fix me.")
-          return .none
-
         case .resetButtonTapped:
-          state.heatingCapacity = nil
+          state.sharedSettings.heatingCapacity = nil
           return .none
 
         case .submitField:
@@ -138,7 +138,7 @@ public struct EquipmentSettingsFormView: View {
       .listRowBackground(Color.clear)
       
       Section {
-         FanTypePicker(selection: $store.fanType)
+        FanTypePicker(selection: $store.sharedSettings.fanType)
           .pickerStyle(.segmented)
       } header: {
         Text("Fan Type")
@@ -154,20 +154,16 @@ public struct EquipmentSettingsFormView: View {
               : "Capacity"
             )
             Spacer()
-            CoolingCapacityPicker(selection: $store.coolingCapacity)
-//            Picker("Cooling Capcity", selection: $store.coolingCapacity) {
-//              ForEach(CoolingCapacity.allCases) {
-//                Text($0.description)
-//                  .tag($0)
-//              }
-//            }
+            CoolingCapacityPicker(
+              selection: $store.sharedSettings.coolingCapacity
+            )
           }
           if store.equipmentType == .furnaceAndCoil {
             GridRow {
               TextLabel("Heating")
               textField(
                 "Heating Capacity",
-                value: $store.heatingCapacity,
+                value: $store.sharedSettings.heatingCapacity,
                 fractionLength: 0
               )
               .focused($focusedField, equals: .heatingCapacity)
@@ -190,7 +186,7 @@ public struct EquipmentSettingsFormView: View {
             TextLabel("Minimum")
             textField(
               "Minimum Pressure",
-              value: $store.ratedStaticPressures.minimum,
+              value: $store.sharedSettings.ratedStaticPressures.minimum,
               fractionLength: 2
             )
             .focused($focusedField, equals: .minimumStaticPressure)
@@ -200,7 +196,7 @@ public struct EquipmentSettingsFormView: View {
             TextLabel("Maximum")
             textField(
               "Maximum Pressure",
-              value: $store.ratedStaticPressures.maximum,
+              value: $store.sharedSettings.ratedStaticPressures.maximum,
               fractionLength: 2
             )
             .focused($focusedField, equals: .maximumStaticPressure)
@@ -210,7 +206,7 @@ public struct EquipmentSettingsFormView: View {
             TextLabel("Rated")
             textField(
               "Rated Pressure",
-              value: $store.ratedStaticPressures.rated,
+              value: $store.sharedSettings.ratedStaticPressures.rated,
               fractionLength: 2
             )
             .focused($focusedField, equals: .ratedStaticPressure)
@@ -221,74 +217,36 @@ public struct EquipmentSettingsFormView: View {
         header("Rated Static Pressure", infoView: .ratedStaticPressures)
       }
 
-//      Section {
-//        Grid(alignment: .leading, horizontalSpacing: 40) {
-//          if store.equipmentMeasurement.equipmentType == .furnaceAndCoil {
-//            GridRow {
-//              TextLabel("Coil")
-//              percentField("Coil Budget", value: $store.budgets.coilBudget.fraction)
-//                .focused($focusedField, equals: .coilBudget)
-//                .onSubmit { send(.submitField) }
-//                .numberPad()
-//            }
-//          }
-//
-//          GridRow {
-//            TextLabel("Filter")
-//            percentField("Filter Budget", value: $store.budgets.filterBudget.fraction)
-//              .focused($focusedField, equals: .filterBudget)
-//              .onSubmit { send(.submitField) }
-//              .numberPad()
-//          }
-//
-//          GridRow {
-//            TextLabel("Return")
-//            percentField("Return Plenum Budget", value: $store.budgets.returnPlenumBudget.fraction)
-//              .focused($focusedField, equals: .returnPlenumBudget)
-//              .onSubmit { send(.submitField) }
-//              .numberPad()
-//          }
-//
-//          GridRow {
-//            TextLabel("Supply")
-//            percentField("Supply Plenum Budget", value: $store.budgets.supplyPlenumBudget.fraction)
-//              .focused($focusedField, equals: .supplyPlenumBudget)
-//              .onSubmit { send(.submitField) }
-//              .numberPad()
-//          }
-//        }
-//
-//      } header: {
-//        VStack {
-//          header("Budgets", infoView: .budgets)
-//          #if os(macOS)
-//          .font(.title2)
-//          .padding(.top, 20)
-//          #endif
-//          FlaggedView(
-//            flagged: Flagged(wrappedValue: store.budgets.total.rawValue, .percent())
-//          )
-//          .flaggedViewStyle(BudgetFlagViewStyle())
-//        }
-//      }
-
-//      Section {
-//        TextField(
-//          "Airflow",
-//          value: $store.updatedAirflow,
-//          fractionLength: 0
-//        )
-//      } header: {
-//        header("Updated Airflow", infoView: .updatedAirflow)
-//      } footer: {
-//        HStack {
-//          ResetButton { send(.resetButtonTapped) }
-//          Spacer()
-//          NextButton { send(.nextButtonTapped) }
-//            .disabled(!store.isValid)
-//        }
-//        .padding(.top)
-//      }
+      Section {
+        VStack(alignment: .leading) {
+          HStack {
+            TextLabel("Includes Filter Drop")
+            Spacer()
+            Toggle("Includes Filter Drop", isOn: $store.includesFilterDrop)
+          }
+          if store.includesFilterDrop {
+            HStack {
+              TextLabel("Filter Drop")
+              Spacer()
+              textField(
+                "Filter Drop",
+                value: $store.sharedSettings.manufacturersIncludedFilterPressureDrop,
+                fractionLength: 2
+              )
+              .focused($focusedField, equals: .manufacturersIncludedFilterPressureDrop)
+              .decimalPad()
+              .padding(.leading, 40)
+            }
+          }
+        }
+      } header: {
+        header(infoView: .manufacturersIncludedFilterPressureDrop) {
+          VStack(alignment: .leading) {
+            Text("Manufacturer's")
+            Text("Filter Pressure Drop")
+          }
+        }
+      }
     }
     .labelsHidden()
     .bind($focusedField, to: $store.focusedField)
@@ -306,23 +264,23 @@ public struct EquipmentSettingsFormView: View {
     }
   }
 
-  private func header(
-    _ title: String,
-    infoView: EquipmentSettingsForm.InfoView
+  private func header<Label: View>(
+    infoView: EquipmentSettingsForm.InfoView,
+    label: @escaping () -> Label
   ) -> some View {
     HStack {
-      Text(title)
+      label()
       Spacer()
       InfoButton { send(.infoButtonTapped(infoView)) }
     }
   }
 
-//  private func percentField(
-//    _ title: LocalizedStringKey,
-//    value: Binding<Double>
-//  ) -> some View {
-//    TextField(title, value: value, format: .percent, prompt: Text(title))
-//  }
+  private func header(
+    _ title: String,
+    infoView: EquipmentSettingsForm.InfoView
+  ) -> some View {
+    header(infoView: infoView) { Text(title) }
+  }
 
   private func textField(
     _ title: String,
@@ -362,37 +320,29 @@ fileprivate extension InfoViewFeature.State {
         Record the cooling and heating capacities of the system.
         """
       )
-//    case .budgets:
-//      self.init(
-//        title: "Budgets",
-//        body: """
-//        Budgeted percentages for static pressure estimations, these generally are set to
-//        reasonable defaults, however you can change them if desired.
-//
-//        Note: These must total up to 100%.
-//        """
-//      )
+    case .manufacturersIncludedFilterPressureDrop:
+      self.init(
+        title: "Filter Pressure Drop",
+        body: """
+        Record the filter pressure drop that the manufacturer includes in their blower performance table, if applicable.
+
+        Sometimes this information is not listed, therefore it may be reasonable to use a sensible default value of '0.1'.
+
+        Note: The value that is set get's deducted from the filter pressure drop when determining the external static pressure of a system.
+        """
+      )
     case .ratedStaticPressures:
       self.init(
         title: "Rated Static",
         body: """
         Record the rated static pressures of the system.
 
-        These are generally found on the nameplate of the equipment or in the installation
-        manual.
+        These are generally found on the nameplate of the equipment or in the installation manual.
 
         The defaults are generally acceptable for most unitary equipment.
         """
       )
 
-//    case .updatedAirflow:
-//      self.init(
-//        title: "Updated Airflow",
-//        body: """
-//        This is used to generated estimated static pressures at the updated airflow
-//        compared to the existing airflow of the system.
-//        """
-//      )
     }
   }
 }
@@ -401,9 +351,11 @@ fileprivate extension InfoViewFeature.State {
   NavigationStack {
     EquipmentSettingsFormView(
       store: Store(
-        initialState: EquipmentSettingsForm.State()
+        initialState: EquipmentSettingsForm.State(
+          sharedSettings: Shared(SharedPressureEstimationSettings())
+        )
       ) {
-        EquipmentSettingsForm()
+        EquipmentSettingsForm()._printChanges()
       }
     )
     #if os(macOS)
diff --git a/Sources/PressureEstimationsFeature/FlaggedMeasurementsList.swift b/Sources/PressureEstimationsFeature/FlaggedMeasurementsList.swift
index 4749eb8..23f3c7a 100644
--- a/Sources/PressureEstimationsFeature/FlaggedMeasurementsList.swift
+++ b/Sources/PressureEstimationsFeature/FlaggedMeasurementsList.swift
@@ -20,12 +20,12 @@ public struct FlaggedMeasurementsList {
   public struct State: Equatable {
     
     @Presents public var destination: Destination.State?
-    @Shared var sharedSettings: SharedSettings
+    @Shared var sharedSettings: SharedPressureEstimationSettings
     public var estimatedMeasurements: IdentifiedArrayOf<FlaggedMeasurementContainer>
     
     init(
       destination: Destination.State? = nil,
-      sharedSettings: Shared<SharedSettings>,
+      sharedSettings: Shared<SharedPressureEstimationSettings>,
       estimatedMeasurements: IdentifiedArrayOf<FlaggedMeasurementContainer> = []
     ) {
       self.destination = destination
@@ -33,6 +33,7 @@ public struct FlaggedMeasurementsList {
       self.estimatedMeasurements = estimatedMeasurements
     }
    
+    #warning("Move to shared settings.")
     public struct FlaggedMeasurementContainer: Equatable, Identifiable {
       public let id: UUID
       public var flaggedMeasurement: EquipmentMeasurement.FlaggedMeasurement
@@ -115,7 +116,7 @@ public struct FlaggedMeasurementsList {
           
         case .addButtonTapped:
           state.destination = .estimationForm(.init(
-            coolingCapacity: state.sharedSettings.coolingCapacity
+            coolingCapacity: state.sharedSettings.equipmentMetadata.coolingCapacity
           ))
           return .none
           
@@ -145,16 +146,20 @@ public struct FlaggedMeasurementsList {
           return .none
           
         case .onAppear:
-          guard let equipmentMeasurement = state.sharedSettings.equipmentMeasurement,
-                let budgets = state.sharedSettings.budgets
-          else {
+          guard let equipmentMeasurement = state.sharedSettings.equipmentMeasurement else {
             return .none
           }
+          if state.sharedSettings.budgets == nil {
+            state.sharedSettings.budgets = .init(
+              equipmentType: state.sharedSettings.equipmentMeasurement!.equipmentType,
+              fanType: state.sharedSettings.equipmentMetadata.fanType
+            )
+          }
           state.sharedSettings.flaggedEquipmentMeasurement = .init(
-            budgets: budgets,
+            budgets: state.sharedSettings.budgets!,
             measurement: equipmentMeasurement,
-            ratedPressures: state.sharedSettings.ratedStaticPressures,
-            tons: state.sharedSettings.coolingCapacity
+            ratedPressures: state.sharedSettings.equipmentMetadata.ratedStaticPressures,
+            tons: state.sharedSettings.equipmentMetadata.coolingCapacity
           )
           return .none
         }
@@ -178,8 +183,8 @@ public struct FlaggedMeasurementsList {
       )
     }
     
-    return .receive(action: \.receive) { [ratedStaticPressures = state.sharedSettings.ratedStaticPressures] in
-      
+    return .receive(action: \.receive) { [ratedStaticPressures = state.sharedSettings.equipmentMetadata.ratedStaticPressures] in
+
       let filterPressureDrop = form.filterPressureDrop != nil
       ? Positive(wrappedValue: form.filterPressureDrop!)
       : nil
@@ -221,8 +226,6 @@ public struct FlaggedMeasurementListView: View {
         } header: {
           HStack {
             Text("Existing Measurements")
-            Spacer()
-//            Button("Edit") {  }
           }
         }
       }
@@ -278,7 +281,7 @@ public struct FlaggedMeasurementListView: View {
  }
 
 #if DEBUG
-private let sharedSettings = SharedSettings(
+private let sharedPressureEstimationSettings = SharedPressureEstimationSettings(
   budgets: .init(equipmentType: .airHandler, fanType: .constantSpeed),
   equipmentMeasurement: .mock(type: .airHandler),
   flaggedEquipmentMeasurement: nil
@@ -290,10 +293,10 @@ private let flaggedMeasurements = IdentifiedArrayOf<FlaggedMeasurementsList.Stat
       id: UUID(0),
       name: "Existing",
       flaggedMeasurement: .init(
-        budgets: sharedSettings.budgets!,
-        measurement: sharedSettings.equipmentMeasurement!,
-        ratedPressures: sharedSettings.ratedStaticPressures,
-        tons: sharedSettings.coolingCapacity
+        budgets: sharedPressureEstimationSettings.budgets!,
+        measurement: sharedPressureEstimationSettings.equipmentMeasurement!,
+        ratedPressures: sharedPressureEstimationSettings.equipmentMetadata.ratedStaticPressures,
+        tons: sharedPressureEstimationSettings.equipmentMetadata.coolingCapacity
       )
     ),
   ]
@@ -305,7 +308,7 @@ private let flaggedMeasurements = IdentifiedArrayOf<FlaggedMeasurementsList.Stat
     FlaggedMeasurementListView(
       store: Store(
         initialState: FlaggedMeasurementsList.State(
-          sharedSettings: Shared(sharedSettings)
+          sharedSettings: Shared(sharedPressureEstimationSettings)
         )
       ) {
         FlaggedMeasurementsList()
@@ -319,7 +322,7 @@ private let flaggedMeasurements = IdentifiedArrayOf<FlaggedMeasurementsList.Stat
     FlaggedMeasurementListView(
       store: Store(
         initialState: FlaggedMeasurementsList.State(
-          sharedSettings: Shared(sharedSettings)
+          sharedSettings: Shared(sharedPressureEstimationSettings)
         )
       ) {
         FlaggedMeasurementsList()
diff --git a/Sources/PressureEstimationsFeature/PressureEstimations.swift b/Sources/PressureEstimationsFeature/PressureEstimations.swift
index 83daaf0..cf0bfe0 100644
--- a/Sources/PressureEstimationsFeature/PressureEstimations.swift
+++ b/Sources/PressureEstimationsFeature/PressureEstimations.swift
@@ -1,9 +1,11 @@
 import ComposableArchitecture
+import DependenciesAdditions
 import SharedModels
 import Styleguide
 import SwiftUI
 import TCAExtras
 
+#warning("Fix shared settings.")
 @Reducer
 public struct PressureEstimationsFeature {
   
@@ -17,17 +19,16 @@ public struct PressureEstimationsFeature {
   @ObservableState
   public struct State: Equatable {
     @Presents public var destination: Destination.State?
+    @Shared(.sharedPressureEstimationSettings) var sharedSettings = SharedPressureEstimationSettings()
     public var equipmentSettings: EquipmentSettingsForm.State
-    public var equipmentMeasurements: EquipmentMeasurementForm.State?
-    
+
     public init(
       destination: Destination.State? = nil,
-      equipmentSettings: EquipmentSettingsForm.State = .init(),
-      equipmentMeasurements: EquipmentMeasurementForm.State? = nil
+      sharedSettings: SharedPressureEstimationSettings = .init()
     ) {
       self.destination = destination
-      self.equipmentSettings = equipmentSettings
-      self.equipmentMeasurements = equipmentMeasurements
+      self._sharedSettings = Shared(sharedSettings)
+      self._equipmentSettings = .init(sharedSettings: self._sharedSettings)
     }
   }
   
@@ -41,7 +42,9 @@ public struct PressureEstimationsFeature {
       case nextButtonTapped
     }
   }
-  
+
+  @Dependency(\.logger["\(Self.self)"]) var logger
+
   public var body: some Reducer<State, Action> {
     Scope(state: \.equipmentSettings, action: \.equipmentSettings) {
       EquipmentSettingsForm()
@@ -57,13 +60,42 @@ public struct PressureEstimationsFeature {
       case let .view(action):
         switch action {
         case .nextButtonTapped:
-          return .none
+          return handleNextButtonTapped(&state)
         }
       }
     }
     .ifLet(\.$destination, action: \.destination)
   }
-  
+
+  private func handleNextButtonTapped(_ state: inout State) -> Effect<Action> {
+    guard state.destination == nil else {
+      return .fail(
+        """
+        Received next button tapped action on equipment settings form, but the destination is not nil.
+
+        This is considered an application logic error.
+        """,
+        logger: logger
+      )
+    }
+    guard state.equipmentSettings.isValid else {
+      return .fail(
+        """
+        Received next button tapped action on equipment settings form, but the form is invalid.
+
+        This is considered an application logic error.
+        """,
+        logger: logger
+      )
+    }
+    state.destination = .equipmentMeasurements(.init(
+      allowEquipmentTypeSelection: false,
+      sharedSettings: state.$sharedSettings,
+      equipmentType: state.equipmentSettings.equipmentType
+    ))
+    return .none
+  }
+
 }
 
 @ViewAction(for: PressureEstimationsFeature.self)
@@ -79,5 +111,30 @@ public struct PressureEstimationsView: View {
     EquipmentSettingsFormView(
       store: store.scope(state: \.equipmentSettings, action: \.equipmentSettings)
     )
+    .navigationTitle("Equipment Settings")
+    .toolbar {
+      NextButton { send(.nextButtonTapped) }
+        .nextButtonStyle(.toolbar)
+        .disabled(!store.equipmentSettings.isValid)
+    }
+    .navigationDestination(
+      item: $store.scope(
+        state: \.destination?.equipmentMeasurements,
+        action: \.destination.equipmentMeasurements
+      )
+    ) { measurementStore in
+      EquipmentMeasurementFormView(store: measurementStore)
+        .navigationTitle("Existing Measurements")
+    }
+  }
+}
+
+#Preview {
+  NavigationStack {
+    PressureEstimationsView(
+      store: Store(initialState: PressureEstimationsFeature.State()) {
+        PressureEstimationsFeature()._printChanges()
+      }
+    )
   }
 }
diff --git a/Sources/PressureEstimationsFeature/SharedPressureEstimationSettings.swift b/Sources/PressureEstimationsFeature/SharedPressureEstimationSettings.swift
new file mode 100644
index 0000000..010fc57
--- /dev/null
+++ b/Sources/PressureEstimationsFeature/SharedPressureEstimationSettings.swift
@@ -0,0 +1,40 @@
+import ComposableArchitecture
+import SharedModels
+
+/// Holds onto shared values for several of the views in this feature.
+@dynamicMemberLookup
+public struct SharedPressureEstimationSettings: Equatable {
+  public var budgets: BudgetedPercentEnvelope?
+  public var equipmentMeasurement: EquipmentMeasurement?
+  public var equipmentMetadata: EquipmentMetadata
+  public var flaggedEquipmentMeasurement: EquipmentMeasurement.FlaggedMeasurement?
+  public var heatingCapacity: Double?
+  public var manufacturersIncludedFilterPressureDrop: Double?
+
+  public init(
+    budgets: BudgetedPercentEnvelope? = nil,
+    equipmentMeasurement: EquipmentMeasurement? = nil,
+    equipmentMetadata: EquipmentMetadata = .init(),
+    flaggedEquipmentMeasurement: EquipmentMeasurement.FlaggedMeasurement? = nil,
+    heatingCapacity: Double? = nil,
+    manufacturersIncludedFilterPressureDrop: Double? = nil
+  ) {
+    self.budgets = budgets
+    self.equipmentMeasurement = equipmentMeasurement
+    self.equipmentMetadata = equipmentMetadata
+    self.flaggedEquipmentMeasurement = flaggedEquipmentMeasurement
+    self.heatingCapacity = heatingCapacity
+    self.manufacturersIncludedFilterPressureDrop = manufacturersIncludedFilterPressureDrop
+  }
+
+  public subscript<T>(dynamicMember keyPath: WritableKeyPath<EquipmentMetadata, T>) -> T {
+    get { equipmentMetadata[keyPath: keyPath] }
+    set { equipmentMetadata[keyPath: keyPath] = newValue }
+  }
+}
+
+extension PersistenceReaderKey where Self == InMemoryKey<SharedPressureEstimationSettings> {
+  static var sharedPressureEstimationSettings: Self {
+    .inMemory("sharedPressureEstimationSettings")
+  }
+}
diff --git a/Sources/PressureEstimationsFeature/SharedSettings.swift b/Sources/PressureEstimationsFeature/SharedSettings.swift
deleted file mode 100644
index 118423f..0000000
--- a/Sources/PressureEstimationsFeature/SharedSettings.swift
+++ /dev/null
@@ -1,37 +0,0 @@
-import ComposableArchitecture
-import SharedModels
-
-
-struct SharedSettings: Equatable {
-  var budgets: BudgetedPercentEnvelope?
-  var coolingCapacity: EquipmentMetadata.CoolingCapacity
-  var equipmentMeasurement: EquipmentMeasurement?
-  var fanType: EquipmentMetadata.FanType
-  var flaggedEquipmentMeasurement: EquipmentMeasurement.FlaggedMeasurement?
-  var heatingCapacity: Double?
-  var ratedStaticPressures: RatedStaticPressures
-  
-  init(
-    budgets: BudgetedPercentEnvelope? = nil,
-    coolingCapacity: EquipmentMetadata.CoolingCapacity = .default,
-    equipmentMeasurement: EquipmentMeasurement? = nil,
-    fanType: EquipmentMetadata.FanType = .constantSpeed,
-    flaggedEquipmentMeasurement: EquipmentMeasurement.FlaggedMeasurement? = nil,
-    heatingCapacity: Double? = nil,
-    ratedStaticPressures: RatedStaticPressures = .init()
-  ) {
-    self.budgets = budgets
-    self.coolingCapacity = coolingCapacity
-    self.equipmentMeasurement = equipmentMeasurement
-    self.fanType = fanType
-    self.flaggedEquipmentMeasurement = flaggedEquipmentMeasurement
-    self.heatingCapacity = heatingCapacity
-    self.ratedStaticPressures = ratedStaticPressures
-  }
-}
-
-extension PersistenceReaderKey where Self == InMemoryKey<SharedSettings> {
-  static var sharedSettings: Self {
-    .inMemory("sharedSettings")
-  }
-}
diff --git a/Sources/SharedModels/CoolingCapacity.swift b/Sources/SharedModels/CoolingCapacity.swift
deleted file mode 100644
index fbf2875..0000000
--- a/Sources/SharedModels/CoolingCapacity.swift
+++ /dev/null
@@ -1,2 +0,0 @@
-import Foundation
-
diff --git a/Sources/SharedModels/EquipmentMeasurement.swift b/Sources/SharedModels/EquipmentMeasurement.swift
index 401cbb5..d7ba7db 100644
--- a/Sources/SharedModels/EquipmentMeasurement.swift
+++ b/Sources/SharedModels/EquipmentMeasurement.swift
@@ -1,8 +1,5 @@
 import Foundation
 
-#warning("Make values non-optional")
-#warning("Need to make air handler external static handle large filter pressure drops.")
-#warning("Add an exterenal static pressure strategy for if the filter is built-in or external")
 public enum EquipmentMeasurement: Equatable {
  
   case airHandler(AirHandler)
@@ -17,7 +14,7 @@ public enum EquipmentMeasurement: Equatable {
     }
   }
   
-  public var externalStaticPressure: Double {
+  public var externalStaticPressure: Positive<Double> {
     switch self {
     case let .airHandler(airHandler):
       return airHandler.externalStaticPressure
@@ -26,47 +23,75 @@ public enum EquipmentMeasurement: Equatable {
     }
   }
 
+  public var manufacturersIncludedFilterPressureDrop: Positive<Double> {
+    switch self {
+    case let .airHandler(airHandler):
+      return airHandler.$manufacturersIncludedFilterPressureDrop
+    case let .furnaceAndCoil(furnaceAndCoil):
+      return furnaceAndCoil.$manufacturersIncludedFilterPressureDrop
+    }
+  }
+
   public struct AirHandler: Equatable {
 
     @Positive
-    public var airflow: Double?
+    public var airflow: Double
 
     @Positive
-    public var returnPlenumPressure: Double?
+    public var manufacturersIncludedFilterPressureDrop: Double
+
+    @Positive
+    public var returnPlenumPressure: Double
     
     @Positive
-    public var postFilterPressure: Double?
+    public var postFilterPressure: Double
     
     @Positive
-    public var postCoilPressure: Double?
+    public var postCoilPressure: Double
     
     @Positive
-    public var supplyPlenumPressure: Double?
+    public var supplyPlenumPressure: Double
     
     public init(
-      airflow: Double? = nil,
-      returnPlenumPressure: Double? = nil,
-      postFilterPressure: Double? = nil,
-      postCoilPressure: Double? = nil,
-      supplyPlenumPressure: Double? = nil
+      airflow: Double,
+      manufacturersIncludedFilterPressureDrop: Double,
+      returnPlenumPressure: Double,
+      postFilterPressure: Double,
+      postCoilPressure: Double,
+      supplyPlenumPressure: Double
     ) {
       self.airflow = airflow
+      self.manufacturersIncludedFilterPressureDrop = manufacturersIncludedFilterPressureDrop
       self.returnPlenumPressure = returnPlenumPressure
       self.postFilterPressure = postFilterPressure
       self.postCoilPressure = postCoilPressure
       self.supplyPlenumPressure = supplyPlenumPressure
     }
-    
-    public var externalStaticPressure: Double {
-      var postFilterAdder = 0.0
-      if let postFilterPressure = $postFilterPressure.positiveValue,
-         postFilterPressure > 0.1 
-      {
-        postFilterAdder = postFilterPressure - 0.1
+
+    public init(
+      airflow: Positive<Double>,
+      manufacturersIncludedFilterPressureDrop: Positive<Double>,
+      returnPlenumPressure: Positive<Double>,
+      postFilterPressure: Positive<Double>,
+      postCoilPressure: Positive<Double>,
+      supplyPlenumPressure: Positive<Double>
+    ) {
+      self._airflow = airflow
+      self._manufacturersIncludedFilterPressureDrop = manufacturersIncludedFilterPressureDrop
+      self._returnPlenumPressure = returnPlenumPressure
+      self._postFilterPressure = postFilterPressure
+      self._postCoilPressure = postCoilPressure
+      self._supplyPlenumPressure = supplyPlenumPressure
+    }
+
+    public var externalStaticPressure: Positive<Double> {
+      var postFilterAdder = Positive<Double>.zero
+      if $postFilterPressure > $manufacturersIncludedFilterPressureDrop {
+        postFilterAdder = $postFilterPressure - $manufacturersIncludedFilterPressureDrop
       }
-      return ($returnPlenumPressure.positiveValue ?? 0)
+      return $returnPlenumPressure
       + postFilterAdder
-      + ($supplyPlenumPressure.positiveValue ?? 0)
+      + $supplyPlenumPressure
     }
   }
   
@@ -145,7 +170,7 @@ public enum EquipmentMeasurement: Equatable {
       .init(
         airflow: checkAirflow(value: measurement.airflow, tons: tons),
         coilPressureDrop: .init(
-          wrappedValue: (measurement.$postCoilPressure.positiveValue - measurement.$postFilterPressure.positiveValue) ?? 0,
+          wrappedValue: (measurement.$postCoilPressure.positiveValue - measurement.$postFilterPressure.positiveValue),
           .result(.good())
         ),
         externalStaticPressure: checkExternalStaticPressure(
@@ -155,7 +180,8 @@ public enum EquipmentMeasurement: Equatable {
         filterPressureDrop: .init(
           value: measurement.$postFilterPressure.positiveValue - measurement.$returnPlenumPressure.positiveValue,
           budget: budgets.filterBudget,
-          ratedPressures: ratedPressures
+          ratedPressures: ratedPressures,
+          ignoreMinimum: true
         ),
         returnPlenumPressure: .init(
           value: measurement.$returnPlenumPressure.positiveValue,
@@ -163,7 +189,7 @@ public enum EquipmentMeasurement: Equatable {
           ratedPressures: ratedPressures
         ),
         supplyPlenumPressure: .init(
-          value: measurement.$supplyPlenumPressure.positiveValue ?? 0,
+          value: measurement.$supplyPlenumPressure.positiveValue,
           budget: budgets.supplyPlenumBudget,
           ratedPressures: ratedPressures
         )
@@ -211,61 +237,61 @@ public enum EquipmentMeasurement: Equatable {
   public struct FurnaceAndCoil: Equatable {
 
     @Positive
-    public var airflow: Double?
+    public var airflow: Double
 
     @Positive
-    public var returnPlenumPressure: Double?
+    public var manufacturersIncludedFilterPressureDrop: Double
+
+    @Positive
+    public var returnPlenumPressure: Double
     
     @Positive
-    public var postFilterPressure: Double?
+    public var postFilterPressure: Double
     
     @Positive
-    public var preCoilPressure: Double?
+    public var preCoilPressure: Double
     
     @Positive
-    public var supplyPlenumPressure: Double?
+    public var supplyPlenumPressure: Double
     
     public init(
-      airflow: Double? = nil,
-      returnPlenumPressure: Double? = nil,
-      postFilterPressure: Double? = nil,
-      preCoilPressure: Double? = nil,
-      supplyPlenumPressure: Double? = nil
+      airflow: Double,
+      manufacturersIncludedFilterPressureDrop: Double,
+      returnPlenumPressure: Double,
+      postFilterPressure: Double,
+      preCoilPressure: Double,
+      supplyPlenumPressure: Double
     ) {
       self.airflow = airflow
+      self.manufacturersIncludedFilterPressureDrop = manufacturersIncludedFilterPressureDrop
       self.returnPlenumPressure = returnPlenumPressure
       self.postFilterPressure = postFilterPressure
       self.preCoilPressure = preCoilPressure
       self.supplyPlenumPressure = supplyPlenumPressure
     }
-    
-    public var externalStaticPressure: Double {
-      ($postFilterPressure.positiveValue ?? 0) + ($preCoilPressure.positiveValue ?? 0)
+
+    public init(
+      airflow: Positive<Double>,
+      manufacturersIncludedFilterPressureDrop: Positive<Double>,
+      returnPlenumPressure: Positive<Double>,
+      postFilterPressure: Positive<Double>,
+      preCoilPressure: Positive<Double>,
+      supplyPlenumPressure: Positive<Double>
+    ) {
+      self._airflow = airflow
+      self._manufacturersIncludedFilterPressureDrop = manufacturersIncludedFilterPressureDrop
+      self._returnPlenumPressure = returnPlenumPressure
+      self._postFilterPressure = postFilterPressure
+      self._preCoilPressure = preCoilPressure
+      self._supplyPlenumPressure = supplyPlenumPressure
+    }
+
+    public var externalStaticPressure: Positive<Double> {
+      ($postFilterPressure - $manufacturersIncludedFilterPressureDrop) + $preCoilPressure
     }
   }
 }
 
-//extension EquipmentMeasurement.AirHandler {
-//  
-//  public enum Key: String, Equatable, CaseIterable {
-//    case returnPlenumPressure
-//    case postFilterPressure
-//    case postCoilPressure
-//    case supplyPlenumPressure
-//    case airflow
-//  }
-//}
-//
-//extension EquipmentMeasurement.FurnaceAndCoil {
-//  
-//  public enum Key: String, Equatable, CaseIterable {
-//    case returnPlenumPressure
-//    case postFilterPressure
-//    case preCoilPressure
-//    case supplyPlenumPressure
-//    case airflow
-//  }
-//}
 fileprivate extension Flagged {
 
   init(
@@ -303,11 +329,11 @@ fileprivate extension Flagged {
 }
 
 fileprivate func checkExternalStaticPressure(
-  value: Double,
+  value: Positive<Double>,
   ratedPressures: RatedStaticPressures
 ) -> Flagged {
   .init(
-    wrappedValue: value,
+    wrappedValue: value.positiveValue,
     .rated(ratedPressures)
   )
 }
@@ -330,6 +356,7 @@ extension EquipmentMeasurement {
     case .airHandler:
       return .airHandler(.init(
         airflow: 1200,
+        manufacturersIncludedFilterPressureDrop: 0.1,
         returnPlenumPressure: 0.3,
         postFilterPressure: 0.6,
         postCoilPressure: 0.9,
@@ -339,6 +366,7 @@ extension EquipmentMeasurement {
     case .furnaceAndCoil:
       return .furnaceAndCoil(.init(
         airflow: 1200,
+        manufacturersIncludedFilterPressureDrop: 0.0,
         returnPlenumPressure: 0.3,
         postFilterPressure: 0.6,
         preCoilPressure: 0.4,
diff --git a/Sources/SharedModels/EquipmentMetadata.swift b/Sources/SharedModels/EquipmentMetadata.swift
index 6507741..d4f6e42 100644
--- a/Sources/SharedModels/EquipmentMetadata.swift
+++ b/Sources/SharedModels/EquipmentMetadata.swift
@@ -3,16 +3,16 @@ import Foundation
 public struct EquipmentMetadata: Equatable {
   public var coolingCapacity: CoolingCapacity
   public var fanType: FanType
-  public var ratedStaticPressure: RatedStaticPressures
+  public var ratedStaticPressures: RatedStaticPressures
 
   public init(
     coolingCapacity: CoolingCapacity = .three,
     fanType: FanType = .constantSpeed,
-    ratedStaticPressure: RatedStaticPressures = .init()
+    ratedStaticPressures: RatedStaticPressures = .init()
   ) {
     self.coolingCapacity = coolingCapacity
     self.fanType = fanType
-    self.ratedStaticPressure = ratedStaticPressure
+    self.ratedStaticPressures = ratedStaticPressures
   }
 
   public enum CoolingCapacity: Double, Equatable, CaseIterable, Identifiable, CustomStringConvertible {
diff --git a/Sources/SharedModels/Flagged.swift b/Sources/SharedModels/Flagged.swift
index b16f053..65b47ae 100644
--- a/Sources/SharedModels/Flagged.swift
+++ b/Sources/SharedModels/Flagged.swift
@@ -1,5 +1,8 @@
 import Foundation
 
+/// Represents a number that can be checked if it is within an acceptable range. It can generate errors or warnings depending
+/// on the current value.
+/// 
 @dynamicMemberLookup
 public struct Flagged: Equatable {
   
diff --git a/Sources/SharedModels/HelperTypes/Positive.swift b/Sources/SharedModels/HelperTypes/Positive.swift
index 48f8e6a..e51f5b1 100644
--- a/Sources/SharedModels/HelperTypes/Positive.swift
+++ b/Sources/SharedModels/HelperTypes/Positive.swift
@@ -5,6 +5,10 @@ public struct Positive<Value> where Value: Numeric, Value: Comparable {
 
   public var wrappedValue: Value
 
+  public init(_ value: Value) {
+    self.wrappedValue = value
+  }
+
   public init(wrappedValue: Value) {
     self.wrappedValue = wrappedValue
   }
diff --git a/Sources/Styleguide/KeyboardStyles.swift b/Sources/Styleguide/KeyboardStyles.swift
index 5fa4a72..c3d3e7f 100644
--- a/Sources/Styleguide/KeyboardStyles.swift
+++ b/Sources/Styleguide/KeyboardStyles.swift
@@ -10,9 +10,13 @@ extension View {
     #endif
   }
 
+  #warning("Fix me.")
+  // The decimal pad autocompletes too quickly in the simulator, needs tested on an actual
+  // device.
   public func decimalPad() -> some View {
     #if os(iOS)
-    self.keyboardType(.decimalPad)
+//    self.keyboardType(.decimalPad)
+    self.keyboardType(.numberPad)
     #else
     self
     #endif
diff --git a/Sources/Styleguide/Styles/ButtonStyles.swift b/Sources/Styleguide/Styles/ButtonStyles.swift
index 9339c08..2007293 100644
--- a/Sources/Styleguide/Styles/ButtonStyles.swift
+++ b/Sources/Styleguide/Styles/ButtonStyles.swift
@@ -88,6 +88,22 @@ extension DefaultNextButtonStyle where ButtonStyle == BorderedProminentButtonSty
   }
 }
 
+public struct ToolbarNextButtonStyle: PrimitiveButtonStyle {
+
+  public func makeBody(configuration: Configuration) -> some View {
+    Button(role: configuration.role, action: configuration.trigger) {
+      configuration.label
+        .foregroundStyle(Color.accentColor)
+    }
+    .labelStyle(ReverseLabelStyle())
+    .buttonStyle(.plain)
+  }
+}
+
+extension AnyPrimitiveButtonStyle<NextButtonType> {
+  public static var toolbar: Self { .init(ToolbarNextButtonStyle()) }
+}
+
 extension AnyButtonStyle where ButtonType == InfoButtonType {
   public static var `default`: Self {
     .init(DefaultInfoButtonStyle<IconOnlyLabelStyle>(labelStyle: .iconOnly))