Features: 1Manufacturing Material: Made of high quality chrome steel material long service life slippy no edges and low noise during operation. 2Good Sealing: Both sides of the double row angular contact ball bearings are designed with seals to keep the lubricating oil in a sealed state. 3High Performance: Uniform hardness wear resistance high temperature resistance and double shielding to avoid contamination. 4Wide Application: Mainly used in textile machinery printing machinery automobile industry household appliances currency detector. 5Easy to Use: Easy to use and fine workmanship. Without any difficult requirements even though you use it for the first time. Specification: Item Type:BallBearingWeight: Approx.223g / 7.9ozMaterial: Chrome SteelInner Diameter: Approx.20mm / 0.8inOuter Diameter: Approx.52mm / 2.0inThickness: Approx.22mm / 0.9in Package List: 1 x Bearing