Four wheeled Adult Safety Rollers are height and width adjustable with front swivel wheels and feature a spring action braking system. They are available in two sizes.The Safety Roller halts in step with user and the braking mechanism engages if user stumbles. Rubber wheels are ideal for indoor and outdoor use. Optional accessories include a seat, basket, oxygen tank holder, forearm platforms, variable resistance tabs, swivel wheel locking brackets, IV pole and extended uprights for additional height.