... OEM service and designed service offered 3. Material: Gcr15 Groove Ball Bearing:1.Ball bearing.Roller bearing. hub bearing 2.material,steel GCR - 15 3.Certificate: ISO ... Alvania R12 and so onSeriesSeries 30200, 30300, 32200, 32300, 33000,6000,6200,6300,6400,51100,51200,51300,51400,DAC,BC, etc ... inspection7.Appearance inspection8.Rust prevention9.Product packaging High quality deep groove ball bearings