2" (50mm) Wheel Diameter Standard 7/16"x7/8" (11mm x 22mm) wire grip ring stem (universal) Hard nylon wheel - Ideal for use on carpet and plastic chair mats Black with Chrome hood Standard 2" replacement casters with chrome top cover. Ideal for use on office chairs, stools, drafting chairs, gaming chairs, tables, file cabinets, and more. These casters look great with a polished aluminum chair base! Note: These are hard wheel casters and are not intended for use on hardwood flooring.