Universal standard stem size: 11mm x 22mm, suitable for 96% of standard size office chairs on the market. (Please confirm your chair size before ordering to ensure this wheel is suitable). 【Wide range of applicable floors】Quiet and smooth, no damage to the floor, strong applicability. Wooden floors, short wool blankets, tiled floors, etc. When rolling in any corner of your office or home, you will feel safe. Easy to install: This kind of wheel is very easy to install without tools. You only need to remove the old wheel, then align the connecting rod of the new wheel with the chair socket and press it to complete the installation. Other advantages: strong load-bearing capacity (the maximum load-bearing capacity of 5 wheels can reach 700 kg), new wear-resistant TPR rubber material, silent sliding does not damage the floor, dust-proof wheel cover (dust-proof rubber cover design on both sides of the wheel, effectively preventing dust and hair).