Rolling bearings use rolling elements to maintain the separation between moving parts to reduce rotational friction and support radial and axial loads. All rolling bearings are open, shielded, or sealed. Rolling bearings are used in a range of applications from agricultural machinery to conveying equipment, robotics, dental equipment, elevators, rolling mills, ship rudder shafts, and aggregate crushers, among others. Feature - Color: Red - Material: Bearing Steel. - Size: 3.9x3.9x0.65cm - Ball Bearings are one of the most widely used rolling bearings. They are used to accommodate radial and axial loads in both directions. - Suitable for all kinds of bike, folding Bicycle, mountain Bike, small rotary motor, office equipment and so on. - With small friction and high-limit speed, Deep Groove Ball Bearings are cost-effective and require little maintenance. - Single-row, pre-lubricated, normal accuracy. - Before purchasing, please use calipers to measure whether the inner diameter of the installation of your own bowl group bearings matches.