Specifications 1. Low noise 2. ISO9001Quality 3. Best after-sale service 4 ... days after the receipt of advancement.SpecificationsSpecifications 1. Low noise 2. ISO9001Quality 3. Best after-sale service 4. ... open, -Z, -2Z, -RS, -2RS.4) Vibration and Noise level: Z1, Z2, Z3. ZV2, ZV3, Z2V2, Z3V3.5) Precition ... level: ABEC1, ABEC3, ABEC5,ABEC7.6) Cage: nylon steel ...