These walkboards constructed of aluminum and plywood are as sturdy as they come. They are seven feet long and 19.25 inches wide, with two hooks on each end that rest on scaffold frames below. They utilize plywood platforms that rest on an aluminum framework of rails, hooks and support ribs. This unit is entirely modular, if any part breaks it can be replaced without having to buy an entirely new unit. They're held together with high-quality zinc plated carriage bolts and nylon backing nuts.