25 X 54 X 13 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-4 Dimensions - 25" Wide - 54" Length - 13" height clearance with a 2" mounting Flange Note: This is the second most standard commonly used size used for fold down attic stairs Used for fold down attic stairs, scuttle Holes and Knee wall doors