1,high quality 2,Super quality and low price 3,ISO standard 4,Delivery in time Ball bearing1) Types: 60 series , 62 series , 63 series .2) Corresponding models range:605-6015,625-6215,6300-6315.3)Material:Gcr15(Chrome steel)--China,(AISI)52100---American ,(Din) 100Cr6---Germany4)Shield/Closure:Plain(Open),Z,ZZ,RS,2RS,UG.5)Vibration and Noisy level: Z1,Z2,Z3,ZV1,ZV2.ZV3.Z1V1.Z2V2.Z3V3.6)Precision ...