The steps of the stairs are wide, so you can raise and lower without worry. The hook part is extendable, so you can set it according to the height of the truck. Includes locking mechanism to stabilize the stair position for safety. The effective inner dimensions of the hook are 2.9 inches (7.4 cm), so it can be hung not only on aori but also on scaffold pipes. Product Specifications: Hook Height: Approx. 45.3 - 57.1 inches (115 - 145 cm); Top Step Height: Approx. 42.9 inches (109 cm); Weight: Approx. 18.3 lbs (8.4 kg); Please check the detailed size image.