... .2) Shield/closure: open bearing, Z, ZZ, RS, 2RS.3) Vibration and Noise level: Z1, Z2, Z3. ZV2, ZV3, Z2V2, Z3V3 ... level: ABEC1, ABEC3, ABEC5,ABEC7.5) Files usd in; Motocycle, Motor, Pump, Fan, Are conditioner, Microwave Oven, Rangehood, sewing machine, massage ...