★Convenient Installation★:Our universal floor safe caster stem diameter is 3/8"(10mm),stem length is 1"(25mm),maybe a rubber mallet needed ,pull out old office caster wheels and push in new premium replacement style caster wheels,and go ★Safe for all Floors★:Unlike other cheap ,low quality caster wheels.Our style casters are made from soft,polyurethane material,they are safe for all floors including hardwood,laminate,tile,carpet,vinyl plank and bamboo flooring,no scratch and mark on the floors ★Smooth&Quiet Rolling★:The caster chair wheels internal bearings are quick rolling and the surface is sleek,wouldn't get stuck by crumbs,hair and grit,you would enjoy smooth and silent moving on the office chair