[Perfect Design Style]: 2.5-inch universal casters, five. The office chair casters are single-row instead of double-row, making it more beautiful and practical for everyone. Our sturdy chair casters are made of heavy-duty steel fabric, precision ball bearings, and transparent PU material, making the office chair more stable and sturdy, giving everyone peace of mind (our insert rod diameter is 11 x 22 mm). [FITS MOST OFFICE CHAIRS]: Our office chair caster replacements will never scratch, stain, or damage your floors. Of course, if you must use a chair cushion, the casters will also work for the cover. Enjoy safe, worry-free gliding on wood, hardwood, laminate, vinyl, tile, and carpet floors all day long.[Easy to Install & Sturdy] - Installing the casters is very simple, no tools required. Just remove the old wheel and push our new wheel into the socket; not compatible with IKEA chairs or some other brand chairs.[Quiet & Smooth Gliding] - The wheels are made of rubber, which has a good cushioning effect and will not produce squeaky friction on the floor during use. Enjoy a smooth and quiet ride with these casters to stay focused and relaxed. Squeaky, wobbly wheels on an office chair are a sign that they are cheap and low-quality.[Perfect Size] The outer layer of the wheels is made of a rubber-like plastic material and covered with soft polyurethane. This soft cover not only prevents damage to the floor, but also allows it to roll freely on the carpet. Mounting hole diameter 8 mm, wheel width 23 mm; 360-degree rotation; can withstand a weight of 200 kg.