[Good quality] The bearings with Precision balls are made of high quality steel. and the casters are made of high quality rubber, which has good strength and durability. and avoid deformation. Office chair casters are sturdy and durable and can be used in desks weighing up to 200 lbs. 350 kg.[Flexible and smooth rolling] High-precision ball bearings on the rollers provide an ultra-stable and quiet ride. Chair Casters Casters are quiet, smooth and non-staining, also suitable for uneven floors. The rotation function at 360 degrees ensures free movement in all directions, very smooth and noiseless, and does not disturb anyone when you are working.[Easy to use. install] The size is 75mm, 10mmx22mm. The casters are easy to roll. install and adapt to most office chairs. After removing old wheel, the new wheelchair wheel can be inserted without tools. However, please check if your chair size fits. product size before purchasing. Compatible with IKEA 10mm chair.[Protect any floor] Hard floor castors use soft polyurethane edges to ensure no marks or scratches are left on any area. Office chair casters are made from made from high quality rubber materials, which can protect all floors, such as vinyl floors, parquet floors, carpets, laminate floors and ceramic floors. >