New. Open bag. By Top Glides. Converts most standard folding walkers into a smooth rolling walkerIt is supposed to have ski glides as an additional attachment but they are missing. The wheels are 8” in diameter and 1.5” rubber tread. Designed for use on a wide range of surfaces including concrete, grass, tile, carpet, hardwood, asphalt, and more. For use with most walkers. 350lb. Weight capacity.