Our bearing have high quality low noise & conpetitive price! Certificates: ISO 9001:2000 Precition level: ABEC1, ABEC3, ABEC5, 1) Materal used: GCr15—China.(AISI)52100—American,(Din)100Cr6—Germany.2) Shield/closure: open bearing, Z, ZZ, RS, 2RS.3) Vibration and Noise level: Z1, Z2, Z3. ZV2, ZV3, Z2V2, Z3V3.4) Precition level: ABEC1, ABEC3, ABEC5,ABEC7.5) Files usd in; Motocycle, Motor, Pump, Fan, ...