40 X 40 X 15 inches The Attic Tent is a specially engineered, patented insulator designed to create an air transfer barrier between your attic and living areas. Main Materials: Nylon Fabric and Polyurethane Form + Flame Retardant AT-8 Dimensions 40" Wide - 40" Length - 15" height clearance with a 2" mounting Flange Can be used for attic openings with these dimensions