... for precision instruments, low noise motors, automobiles, motorcycles, and other common machinery, as a widely used type of bearing in machinery ... speedBBCSealed grease lubrication CBADustproofCBAWaterproofDCBA.ExcelientB.Good C.Fair D.Poor Series:SeriesBore diameterVariant structure600010~120Z,2Z,RZ,2RZ,RS1,2RS1,N ... doubt please contacto to us. Deep groove ball bearing 6400 Series