Features COVERS TO PREVENT DUST: There are steel dust covers on both sides to prevent dust and foreign objects from entering LOW FRICTION AND VIBRATION: Deep groove ball bearing possess simple configuration, high speed, low friction coefficient, low vibration and noise DOUBLE SHIELDED: Ball bearings have uniform hardness, wear resistance, high temperature resistance and double shielding to avoid the entry of contaminants and save lubricant APPLICABLE FIELDS: Used for papermaking machinery, reduction gear, railway vehicle axles, steel machine gear box bearing housings, rolling mill rolls, crushers, vibrating screens, printing machinery, woodworking machinery, various industrial reducers, ve 20PCS IN TOTAL: The package contain a total of 20pcs, enough for you to replace and use, very convenient Specification: Item Type: Deep Groove Ball Bearing Model: 6901Z Product Size: Inner Diameter: Approx. 12mm / 0.47in Outer Diameter: Approx. 24mm / 0.94in Thickness: Approx. 6mm / 0.24in Applicable Fields: Papermaking machinery, reduction gear, railway vehicle axles, steel machine gear box bearing housings, rolling mill rolls, crushers, vibrating screens, printing machinery, woodworking machinery, various industrial reducers, vertical self aligning bearings with seats Package List:20 x Deep Groove Ball Bearing Package List 20 x Deep Groove Ball Bearing