The cart is made of fully welded unitized construction with an overall carrying capacity of 500 pounds. The corner legs are made of 16-gauge angle stainless steel. The shelves are constructed of 20-gauge stainless steel with long shelf edges double hemmed for extra strength, and electronically spot welded to the upright legs at all points. Comes with a stainless steel push handle that is welded to the frame, and the corner bumpers are mounted to the front legs and the ends of push handle. The cart has an independent galvanized steel dolly frame that is fastened to the bottom with 8 screws. Four 4" swivel casters are mounted directly to the dolly frame. Models 444 and 459 have four 5" diameter swivel casters with non-marking polyurethane wheels. Comes with triangular welded assembly stainless steel reinforcing gussets that are welded to the four bottom corners. Top shelf is made from 16-gauge angle reinforcements that are welded to the long shelf edges.