The Lennox 13U56 Induced Draft Flue Transition is an original equipment manufacturer (OEM) component designed for compatible Lennox gas furnaces. It connects the combustion air inducer outlet to the flue vent, directing combustion gases toward the exhaust system. This component supports proper venting and helps maintain safe, efficient furnace operation. https://www.partshnc.com/lennox-13u56-inducer-draft-flue-transition