These oversized units are perfect for large jobs. Ideal for oversized cartons, boxes, parts and supplies. A spring loaded steel ladder for sure, safe climbing and loading is featured on both the SPS and SPA models. Steps have nonskid footing with self-cleaning surface. Each unit features 3 shelf. Standard 4" x 2" mold-on-rubber casters, 2 rigid and 2 swivel with brake. Built of durable steel or aluminum construction. Steel units have a blue baked-in powder coated finish for toughness while the steel ladders included on the aluminum units have a baked-in silver powder coat finish.