DGQ 5/8" Roller Ball Transfers Set of 6 Swivel Ball Caster Furniture Trolley Screw Mounted Round Casters DGQ swivel ball caster; Color : Silver tone; 5/8 inch hardened Steel balls rotating on 1/8 inch internal bearings. 360 Universal transfer bearings - load rating is 55 pounds Size:19mm high x 29mm wide x 50mm long(base mounting bracket) For use bearing side up only, not for use as castor wheels,not for the wooden floor. Widely use: You can use these rolling ball transfers to conve your lines installing, home appliance manufacturing factories, heavy load material handlings equipment,transmission system, feeding system,processing machinery and packaging machinery auxiliary equipment,etc. Pack of 6pcs.