One-button folding mechanism offers quick, convenient operation.Folding mechanism can be operated with one hand.Aluminum; no wheels.Case of 4.G30760P: 300-lb. (136 kg) Weight capacity; Approximate user height, 5'5"-6'4" (165 cm-193 cm); Width inside hand grip, 17.25" (44 cm); Height adjustment, 31.5"-38.5" (80 cm-98 cm); Folded width, 4.5" (11 cm).MDS86615: 250-lb. (113 kg) Weight capacity; Approximate user height, 5'-6' (152 cm-183 cm); Width inside hand grip, 18" (46 cm); Height adjustment, 32"-36" (81 cm-91cm); Folded width, 4.5" (11 cm).