The NEW patented, push-button locking system, NEW tubular polycarbonate handle and 6" roller bearing semi-pneumatic wheels make this cart quite attractive yet it remains the strongest of them all. Its chrome plated solid steel wheel guards protect loads. It has a chrome plated solid steel sliding base lock and chrome plated solid steel wire, curb/stair slides. An adjustable lock on permanently attached elastic cords prevents load shifting and a patented rear platform with 3" swivel casters folds down into locked position to function as a 4 wheel dolly.