Perfect for easy and stable access to the water, these marine-grade ladders are made of an extra strong 6000 series aluminum alloy to help prevent corrosion. These retractable ladders slide up above the water line to prevent marine growth. Double rung locking mechanism keeps the ladder stable when climbing out of the water. 21" wide. Extends 12" onto dock. 21" high handles. 750-lb. capacity. Standard 2" wide step. 12" between each rung. Mounting hardware not included. Corrosion-resistant 750-lb. capacity 21"" wide | Dockmate Standard 3-Step Dock Lift Ladder