UNIVERSAL SIZE FOR 99% CHAIRS - Set of 5 premium office chair swivel castors . Universal shaft size: 7/16 inch wide x 7/8 inch high (11 x 22mm) roller shaft fits up to 99% chairs (office chairs, computer chairs, desk chairs)Safe for all floors - swivel castors do not require any plastic office chair mats at all. The office chair castors can slide securely on your wood, vinyl, carpet, hardwood, tile and laminate floors without causing scratches or noise.Two-step installation-Easy installation without additional tools and no matter where you are. Simply set off the chair, pull out the old wheels and then insert the wheels into the slots. It doesn't even take 5 minutes to give your chair a new look.Stability and durability: reinforced bracket uses high-strength punching steel to ensure the durability of the wheels. Each wheel can hold up to 50 kg and the total load capacity is 175 kg. Meets the long-term daily use of most people and several occasions.Quiet and smooth - The rollerblade roller is made of shock-absorbing polyurethane, and you will enjoy a quiet, smoother glide through your home office Color: black + transparentmaterial: plasticWheel diameter: 50MMPackage Contents:5 x Chair WheelsOnly the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.