Our steel garage door Model 183 is constructed of heavy-duty steel and features a standard panel design with a wood grain embossment to enhance the appearance of your door. The polystyrene insulation provides a 7.4 R-value for enhanced thermal efficiency of your garage space. A vinyl interior backing of the door provides a finished appearance. Model 183 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.