NSK BEARINGS 6220-ZZ 1.high speed,low noise 2.NSK 2RS Ball Bearings 3.NSK ZZ Bearings 4.NSK Agent certificate Characteristic of NSK bearing:1. Seal form: open style, Z, ZZ, RS, 2RS, 2RZ2. Bearing stop ring: N,NR3. Class of precision: ABEC-1, ABEC-3, ABEC-5, ABEC-74. Vibration rank: V1, V2, V3, V45. Noise rank: Z1,Z2,Z3,Z465.6. Internal elimination code: C0, C2, C3, C4, C57. Bearing material: ...