... grease lubrication CBADustproofCBAWaterproofDCBA.ExcelientB.Good C.Fair D.Poor Series:SeriesBore diameterVariant structure600010~120Z,2Z,RZ,2RZ,RS1,2RS1 ... ,N,NR,ZN,RZN620010~120Z,2Z,RZ,2RZ,RS1,2RS1,N,NR,ZN,RZN630010~120Z,2Z ... ,RZ,2RZ,RS1,2RS1,N,NR,ZN,RZN640010~120N,NRParameter:ModelBore Size(mm)Outside ... please contacto to us. Deep groove ball bearing 6400 Series