Designed to fit front-wheeled walkers with 1" to 1-1/8" tubing diameter, Penco Walker Glides feature a 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. Manufactured in the United States.