These units are built for transporting big loads of banquets, catering, and bussing. The solid shelves have marine edges that add strength and contain spills. Framework is constructed of 1 3/4" x 1 3/4" x .100 wall Queen Mary Tube. Shelving options available in both stainless steel and aluminum models. Base is constructed out of 1 3/4" x 1 3/4" x .70" wall tubing. Caster wheels included: four 8” platform type casters— two swivel (#C526) two rigid (#C527). Each Unit Is Equipped With A Full Perimeter Bumper.