Our steel garage door Model 1600 (391/399) features a standard panel design or a long panel design with an embossed wood grain texture to enhance the appearance and durability of your door. The polystyrene insulation provides a U-factor of .23 (9.8 R-value) for enhanced thermal efficiency of your garage space. A steel interior backing of the door provides a durable, finished appearance. Model 1600 steel garage doors come with a limited lifetime warranty which means they are built to last. A wide variety of window options are also available for these steel garage doors.