The Nimbo Posterior Walker - Youth Size - Knight Blue, has a lightweight aluminum frame, is height adjustable and can be used in anterior position. Its one-directional rear 5" wheels with aluminum ratchet and pin mechanism adhere to any surface and will not allow the Nimbo to slide backwards. The anti-reverse override bracket can disengage the one-directional rear wheels and allow forward & reverse mobility. Front swivel 4.5" wheels enhance maneuverability and ease of turning. A locking mechanism easily switches front wheels from swivel to non-swivel. Each wheel can be independently adjusted. This walker has a 150 pound weight capacity.