The Reznor 210930 Door Liner helps protect the access door while supporting efficient HVAC equipment operation. This replacement door liner is designed to fit compatible Reznor heating units, providing an insulating and protective barrier on the inside of the equipment door. It works by helping reduce heat transfer and shielding the door from exposure to high operating temperatures, c... https://www.partshnc.com/210930-reznor-door-liner