The Therma Series Commercial/Industrial insulated steel garage doors are rugged and beautiful. They are designed to have a sleek and appealing appearance with great weather resistance. Therma Series doors are made with a sandwich type construction, steel outer skins are formed and then pressure bonded to a polystyrene core giving the door maximum strength, a natural Therma Break and superior insulating efficiencies. Three insulating values are available - R10.4, R12, and R16.