1. Important! Before purchasing, you must determine the correct wheel size to the nearest millimeter! These wheels have a 10mm x 22mm shaft. (They fit IKEA chairs). 2. Safe for all hard floors. Protect your floor with our soft yet robust polyurethane wheels for your floors. The wheels leave hardly any scratches on the floor, perfect for tile, parquet, laminate, wood, marble, granite, stone, concrete, or vinyl floors. 3. Silent, robust. The durable polyurethane wheels for chairs wear and glide silently thanks to our swivel casters. Our chair wheels for heavy chairs are made of industrial steel, precision ball bearings, and durable chair wheels are made of polyurethane. They can carry loads of up to 295 kg! Strong and robust. 4. Easy installation. The wheels are quick and easy to install without tools. Remove the old office chair wheels and push in the new wheels until the shaft is firm and secure. Note: The data are all manual measurements, please allow 1-3 cm error, due to light and screen differences there may be some color difference, depending on the physical object received. Shipping quantity: (according to the main picture) Buying our products not only means having high-quality goods, but also that you can enjoy our thorough customer service. Our customer service is always available to provide you with help and support at any time.