diff --git a/src/PepperDash.Essentials.Core/DeviceTypeInterfaces/IHasSurroundSoundModes.cs b/src/PepperDash.Essentials.Core/DeviceTypeInterfaces/IHasSurroundSoundModes.cs
index 85b01319..c1c4ec86 100644
--- a/src/PepperDash.Essentials.Core/DeviceTypeInterfaces/IHasSurroundSoundModes.cs
+++ b/src/PepperDash.Essentials.Core/DeviceTypeInterfaces/IHasSurroundSoundModes.cs
@@ -11,8 +11,10 @@ namespace PepperDash.Essentials.Core.DeviceTypeInterfaces
     /// Describes a device that has selectable surround sound modes
     /// </summary>
     /// <typeparam name="TKey">the type to use as the key for each input item. Most likely an enum or string</typeparam>
-    public interface IHasSurroundSoundModes<TKey>: IKeyName
+    public interface IHasSurroundSoundModes<TKey, TSelector>: IKeyName
     {
         ISelectableItems<TKey> SurroundSoundModes { get; }
+
+        void SetSurroundSoundMode(TSelector selector);
     }
 }
diff --git a/src/PepperDash.Essentials.Devices.Common/Displays/MockDisplayInputs.cs b/src/PepperDash.Essentials.Devices.Common/Displays/MockDisplayInputs.cs
index 9035508a..f6fb7bc0 100644
--- a/src/PepperDash.Essentials.Devices.Common/Displays/MockDisplayInputs.cs
+++ b/src/PepperDash.Essentials.Devices.Common/Displays/MockDisplayInputs.cs
@@ -10,20 +10,20 @@ namespace PepperDash.Essentials.Devices.Common.Displays
 {
     public class MockDisplayInputs : ISelectableItems<string>
     {
-        private Dictionary<string, ISelectableItem> _inputs;
+        private Dictionary<string, ISelectableItem> _items;
 
         public Dictionary<string, ISelectableItem> Items
         {
             get
             {
-                return _inputs;
+                return _items;
             }
             set
             {
-                if (_inputs == value)
+                if (_items == value)
                     return;
 
-                _inputs = value;
+                _items = value;
 
                 ItemsUpdated?.Invoke(this, null);
             }