Wheel materials are made of high-quality solid polyurethanes, which are high mechanical strength, wear resistance, shock absorption and low-noise.<br> Caster stem is supported by steel sets of double ball bearings, making the wheel more solid and endurable. <br> Double hard steel brackets support HEAVY DUTY, holding over 100 lb per wheel， supports up to 500 lbs as a set of 5, the STRONGEST chair wheels on Amazon.<br> Work on any hardwood, ceramic, wood, carpet, cement floors without Scratching.<br><br> Stem Diameter:7/16"(11mm)<br> Stem Length:7/8”(22mm)<br> Wheel diameter: 2inch(50mm)<br> Wheel width: 24mm <br> Installation: Push-in type<br> Brake: No <br><br> <b> Package includes:</b> 5 pack of Replacement Chair Casters<br> We are committed to providing friendly customer service, please be assured to purchase.