These are our service carts that make mobility of heavy machine parts and tools and dies from shop to assembly areas easy. Uprights are made from 2 inch by 2 inch x.25 inch angle with 12 gauge heavy duty shelves. A handle is provided for steering. The sturdy 6 inches high x 2 inches wide swivel with brake and ridged polyurethane casters make maneuvering easy.//These models come with 3 welded shelves. The shelves are punched to fit you tool and die needs. There are also 2 vise shelves on the cart to work from.