The Stander Replacement Ski Glides are made of a thick wear resistant plastic that will allow you to roll smoothly over any surface. These replacement glides work with the Stander EZ Fold N' Go Walker and the Able Life Space Saver Walker. To replace your current glides, loosen the old screws that are found towards the feet of your walker. Pull the old glides out, and replace with your new glides. Tighten the screws with your included wrench.4 Pack Stander #4302 Walker Replacement Rear Glides, #4300 and #4200 Compatible