The Penco Walker Glides are designed to fit front-wheeled walkers with 1 inch to 1 1/8 inch tubing diameter. Penco Walker Glides feature a patented, self-fitting mechanism for easy installation. Made of durable, high density resin for use on all walking surfaces. The ski design allows for easy movement over thresholds and slight elevation changes without snagging or the need to lift the walker. The self-fitting mechanism and stainless steel tightening bolt keep the glides safe and secure. Penco Walker Glide features patented, self-fitting mechanism for easy installation. Improves mobility when used in conjunction with wheels on the front legs of standard walkers. Construction: durable plastic material.