Only Compatible with IKEA Chairs: Make sure your chair's shaft size is 10*20.5mm, otherwise these wheels will not be compatible with your chair. High Load Capacity: Each wheel can bear up to 30 kg, and all four wheels can bear a maximum load of 50 kg. Safe and stable, suitable for all users. Smooth and Quiet: Smooth and quiet gliding is a primary factor for office chair wheels. These wheels are very flexible when rolling the chair; made of high-quality rubber, they are extremely quiet, making them ideal for the office. Suitable for all floors: Made of nylon and rubber, these wheels are designed to protect hardwood floors, composite floors, tiles, slate, and all other hard floors from damage and scratches. Easy Installation: Just follow a few simple steps; no tools are required, and anyone can easily install them. Note: 1. Manual measurement; please allow some margin of error. 2. Due to differences in lighting and screen, the color of this product may differ slightly from the image.