TruGuard 2-in-1 convertible glides is made with premium quality felt backed by durable foam for repeated use on hard surface floors. Can be used independently on hard surface floors, or combined with the 4" round shell glides on floor surfaces such as carpeting. Can be left under furniture for easy movement during cleaning. 8 pack 3-1/2" - 4" Shape: Round 3-1/2" heavy duty reusable round felt glides Made with premium quality felt backed by durable foam for repeated use on hard surface floors Can be used independently on hard surface floors, or combined with the 4" round shell glides on floor surfaces such as carpeting Glides can be left under furniture for easy movement during cleaning Remove & store until needed again.