Premium Caster Office Chair Caster Wheel, Black, Set of 5 (ZT08) This Premium Casters are made to Protect Hardwood, Laminate, Tile, Slate, and all other Hard Floors Heavy Duty Office Chair Caster Wheels Maximum Weight Rating: 100 lbs EACH and 500 lbs as a set of 5 Works Perfect On Carpets and any Hard Floors. Made with Polyurethane Material Fits Most Office Chair Models Available - Stem diameter: 7/16"(11mm), stem length: 7/8"(22mm) Easy pull and snap installation - 5 years Warranty - Free Replacement or MoneyBack Guarantee