Patented, push-button locking system (ABS material). Automotive grade ABS plastic tubular handle. 5" roller bearing rubber wheels. Chrome plated solid steel wheel guards. Raised, chrome plated steel wire platform to protect loads. Chrome plated solid steel wire, curb/stair slides. Chrome plated solid steel sliding base lock. Adjustable lock permanently attached on elastic cords to prevents load shifting. Patented rear platform with swivel casters folds down into locked position so that unit functions as a 4 wheel dolly. Weight capacity: 225 lbs. Overall dimensions: Height: 45.5"; Base: 15.5" x 9" Storage dimensions: Height: 21.5"; Width: 15.75"; Depth: 5.5" Weight: 12.5 lbs. OPTIONAL: Innovative design allows incorporation of optional extended rubber grip bike handle.