1、COVERS TO PREVENT DUST: There are steel dust covers on both sides to prevent dust and foreign objects from entering 2、LOW FRICTION AND VIBRATION: Deep groove ball bearing possess simple configuration, high speed, low friction coefficient, low vibration and noise 3、DOUBLE SHIELDED: Ball bearings have uniform hardness, wear resistance, high temperature resistance and double shielding to avoid the entry of contaminants and save lubricant 4、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, vertical self aligning bearings with seats 5、20PCS IN TOTAL: The package contain a total of 20pcs, enough for you to replace and use, very convenient 20 x Deep Groove Ball Bearing Item Type: Deep Groove Ball BearingModel: 6901ZProduct Size: Inner Diameter: Approx. 12mm / 0.47inOuter Diameter: Approx. 24mm / 0.94inThickness: Approx. 6mm / 0.24inApplicable 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