Index: Ringtoets/Piping/src/Ringtoets.Piping.Forms/PropertyClasses/RingtoetsPipingSurfaceLineCollectionProperties.cs
===================================================================
diff -u -r922e186b7941457f71de9b4909fa2490f36a1c63 -r66b07e7599319ea71ff109d8303f74a4a2e5f71c
--- Ringtoets/Piping/src/Ringtoets.Piping.Forms/PropertyClasses/RingtoetsPipingSurfaceLineCollectionProperties.cs	(.../RingtoetsPipingSurfaceLineCollectionProperties.cs)	(revision 922e186b7941457f71de9b4909fa2490f36a1c63)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Forms/PropertyClasses/RingtoetsPipingSurfaceLineCollectionProperties.cs	(.../RingtoetsPipingSurfaceLineCollectionProperties.cs)	(revision 66b07e7599319ea71ff109d8303f74a4a2e5f71c)
@@ -30,17 +30,17 @@
 namespace Ringtoets.Piping.Forms.PropertyClasses
 {
     /// <summary>
-    /// ViewModel of <see cref="ObservableCollectionWithSourcePath{T}"/> of <see cref="RingtoetsPipingSurfaceLine"/> for properties panel.
+    /// ViewModel of <see cref="ObservableUniqueItemCollectionWithSourcePath{TObject}"/> of <see cref="RingtoetsPipingSurfaceLine"/> for properties panel.
     /// </summary>
-    public class RingtoetsPipingSurfaceLineCollectionProperties : ObjectProperties<ObservableCollectionWithSourcePath<RingtoetsPipingSurfaceLine>>
+    public class RingtoetsPipingSurfaceLineCollectionProperties : ObjectProperties<ObservableUniqueItemCollectionWithSourcePath<RingtoetsPipingSurfaceLine>>
     {
         /// <summary>
         /// Creates a new instance of <see cref="RingtoetsPipingSurfaceLineCollectionProperties"/>.
         /// </summary>
         /// <param name="collection">The collection for which the properties are shown.</param>
         /// <exception cref="ArgumentNullException">Thrown when <paramref name="collection"/>
         /// is <c>null</c>.</exception>
-        public RingtoetsPipingSurfaceLineCollectionProperties(ObservableCollectionWithSourcePath<RingtoetsPipingSurfaceLine> collection)
+        public RingtoetsPipingSurfaceLineCollectionProperties(ObservableUniqueItemCollectionWithSourcePath<RingtoetsPipingSurfaceLine> collection)
         {
             if (collection == null)
             {