Polyurethane Office Chair Caster Wheels for Hardwood Floors - Standard Stem Diameter: 7/16", Stem Length: 7/8" - Set of 5 - Gray Edge Heavy Duty Office Chair Caster Wheels Maximum Weight Rating: 100lb per wheel Lithium based grease lubricated for smooth movement Stem diameter: 7/16(11mm), stem length: 7/8(22mm) fits most office chair models sold worldwide. Replace broken or worn wheels - Make your old chair new again!