The 288 Series enhanced thermal efficiency and handsome good looks make it one of the best-selling insulated doors.  A layer of styrene foam insulation yields R-values up to 4.37, while also providing a measure of soundproofing.  Galvanized steel end and center stiles, coupled with tongue-and-groove construction on the sections, lend strength with minimal weight. The door's textured steel exterior and vinyl-backed interior gives a finished appearance both inside and out.