Rough Opening: 22 1/2" x 54" x 10'Ceiling Hgt. Range (A): 105" - 120"Landing Space (B): 73"Projection (C): 79"Step W x L x Facing: 3 3/8" x 12 5/8" x 3/4"Side Rail W x D: 3 1/2" x 3/4"Door Panel W x L x D: 20 3/4" x 52 1/4" x 1/4"