1.Ball bearing.Roller bearing. hub bearing 2.material,steel GCR - 15 3.Quality authentication ISO 9001:2000 4.Hardness:62 Greese/OilAs you requirement, such as SRL ,PS2, Alvania R12 and so on SeriesSeries 30200, 30300, 32200, 32300, 33000,6000,6200,6300,6400,51100,51200,51300,51400,DAC,BC, etc. Ring MaterialChrome Steel ,Carbon steel,Stainless steel Tolerance gradeGB/T307.1-205 ID Size 10mm~280mm ...