Alpine's Super-Imposed (double door) provides a unique method for getting the best of both worlds in one installation. The Super Imposed is a rolling door and rolling grille combination fixed on a common bracket, making it perfect for applications with differing seasonal or security needs. As an additional feature, the rolling grille can be substituted with a perforated or insulated door for increased protection. Consult Alpine's Engineering Department to obtain proper clearance requirements for a particular opening.