... Z2,Z3,Z4Vibration level:V1,V2,V3,V4Hardness of the bearing:HRC59-6ApplicationAutomotive,Office equipment,Electric applicance,Electronics equipment,Optical instrument ... .There are three types of such closed bearings:shielded bearings,contact sealed bearings,and noncontact sealed boarings .Package1.Carton 2.Wooden ... ,Pioneering and Innovative5.Welcome to inquiry . Stainless steel deep groove ball bearing