Rated for 250 pound load capacity. Pre-assembled, contains installation kit and instructions. Extra corner bracing keeps stairway frame square. Double-hinged rail joints, steps with wire rod supports, and full width door hinge for strength and durability.EZ-Hang Strap system acts as temporary supports for quick and easy installation. Installation kit includes EZ-Hang Strap system, 36 in pull cord, 4 support straps, pendant with washer, 4 in x 6 in plywood shim (for final squaring only), eight 7/8 in roofing nails, 3/16 in Meranti plywood door, and installation instructions. Not for homes with roof trusses unless engineer is consulted for approval. Canada compliant.