Braeburn 5390 Remote Indoor Temperature Sensor Contemporary Style for Any Decor Enables Indoor Control Functions on the following Braeburn Thermostat Models:  3020, 3220, 3300, 5020, 5220, 5300, 5310, 5320, 5400, 6100, 6300, 6400 Use in Averaging or Stand Alone Mode Dimensions: 3″ W X 2.5″ H X 15″16″ D