The Windsor Series is the only kiln dried southern yellow pine lumber. The molded handrail and eased-edge stiles enhance the appearance. Windsor stairway is the only stairway produced with 1" x 4" stiles and treads. Fully assembled and ready-to-install with instructions. Full width piano hinge across the frame at the head of the stairs. The springs expand uniformly under load and are hand tool adjustable for safety and reliability. No. BET89: Series: Windsor, Material: Wood, Rough Opening: 22-1/2" x 54", Load Rating: 250 lbs, Finished Clearance: 20-1/2" x 52", Clearance Between Springs: 17", Ceiling Height: 8'9", Stile Size: 1" x 4", Tread Size: 1" x 4" x 13-5/8", Pkg Qty: 1, Package Type: Box No. BET100: Series: Windsor, Material: Wood, Rough Opening: 22-1/2" x 54", Load Rating: 250 lbs, Finished Clearance: 20-1/2" x 52", Clearance Between Springs: 17", Ceiling Height: 10'4", Stile Size: 1" x 4", Tread Size: 1" x 4" x 13-5/8", Pkg Qty: 1, Package Type: Box No. BE89: Series: Windsor, Material: Wood, Rough Opening: 25-1/2" x 54", Load Rating: 250 lbs, Finished Clearance: 23-1/2" x 52", Clearance Between Springs: 20", Ceiling Height: 8'9", Stile Size: 1" x 4", Tread Size: 1" x 4" x 16-1/2", Pkg Qty: 1, Package Type: Box No. BE100: Series: Windsor, Material: Wood, Rough Opening: 25-1/2" x 54", Load Rating: 250 lbs, Finished Clearance: 23-1/2" x 52", Clearance Between Springs: 20", Ceiling Height: 10'4", Stile Size: 1" x 4", Tread Size: 1" x 4" x 16-1/2", Pkg Qty: 1, Package Type: Box