Whitmor Wheels for Whitmor Supreme Shelving Units - Heavy Duty Supports Up To 500 Pounds (Set of 4) Set of 4 wheels fit Whitmor Supreme style shelving units with 1 inch tubes All wheels have bumpers to protect walls; 2 wheels lock for added stability Heavy duty wheels support up to 500 pounds when evenly distributed on shelves Assembled Dimensions: 4.5" x 2" x 4.88" inches Your favorite Whitmor Supreme Shelves can now become mobile Quickly and easily add to any Whitmor Supreme shelving Wheels screw in for easily assembly Whitmor's Service Guarantee - we stand by our products, if you have any problems, contact us for help