This is a BRAND NEW Heat Exchanger Upgrade Kit for Coleman DGAT Furnaces. The Coleman DGAT furnaces (models that start with "DGAT") had a massive recall on their heat exchangers. Upon inspection, if the heat exchanger was not damaged, this upgrade kit was installed to prevent damage. The upgrade kit includes a stainless steel lining for a portion of the heat exchanger as well as a large bracket with a limit switch that is inserted near the exterior of the heat exchanger. Kit comes with instructions. Thanks for looking and good luck!