Features RUBBER SEALING: These deep groove ball bearings are sealed by double sided rubber, which prevent impurities from entering, could also save lubricant. BEARING STEEL MATERIAL: The ball bearings are made of premium bearing steel, steel structure makes them highly sturdy and will not deform under heavy load. PRECISE SIZE: The ball bearings have high machining accuracy, with accurate inner diameter of 30mm, outer diameter of 62mm and thickness of 16mm. EXCELLENT PERFORMANCE: Deep groove ball bearing has the advantages of low noise, fast heat dissipation, low friction, high speed and high temperature resistance. MULTI USAGE: Ball bearings could be widely used in industrial machinery, motorcycle, automobile, electric tool, mechanical equipment and other fields. Specification: Item Type: Deep Groove Ball Bearing Material: Bearing Steel Inner Diameter: Approx. 30mm/1.18in Outer Diameter: Approx. 62mm/2.44in Thickness: Approx. 16mm/0.63in Package List: 2 x Deep Groove Ball Bearing Note: Please allow slight size error due to manual measurement. Thanks for your understanding. Package List 2 x Deep Groove Ball Bearing