"Alternating-tread stairs have a unique design that offers a shorter span than traditional steps. Ships knockdown for lower freight costs. U.S.A. Base Size W x D in. 23 1/2 x 36 1/2, Step Depth in. 10 1/2 excluding top step, Top Width in. 23 1/2. Features handrail on each side of unit Dual safety chain at the top of the stair and formed steel steps with raised surfaces for better traction"