Features: Smooth and Quiet Ride - The 2.5 inch style wheels work great on hardwood, tile and even carpet. All parts are made from high quality and provide the smoothest maneuverability. Compatible With All The Top Major Brands - 7/16" (11mm) x 7/8" (22mm) universal stemworks will with for Herman for Miller Aeron, Hon, Galam, for Serta, Lane, Humanscale Freedom, the gaming chair and for Steelcase, Knoll ergonomic office chairs. Easy Installation - Our wheels will fit most standard office chairs that are made in North America (US and Canada). Please measure your old caster first. To Installation - Just for pop off your old wheels (you may grip them with a glove or towel) and push on your new style wheels. Bonus Round - Gives your old chairs new life. Gives your new chairs upgraded performance Whisper quiet operation. PU wheels will NEVER scratch wood floors Upgrade your office wheel chairs with our 2.5" style wheels for your office chair. Specifications: Material: PU Stem Size: 11x22mm/0.43x0.87" Wheel Diameter: 63mm/2.48"(Approx.) Wheel Thickness: 2.4cm/0.94" Quantity: 1 Pc Note: Please allow 1-3mm error due to manual measurement. pls make sure you do not mind before you bid Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! No Retail Package Package Includes: 1 x Rolling Caster