... . 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 ... ,V3,V45. Innder windage code: C0,C2,C3,C4,C56. Precision Grades: P0,P6,P5,P4,P2(ABEC1,ABEC3,ABEC5,ABEC7 ... and gland6.Noise inspection7.Appearance inspection8.Rust prevention9.Product packaging High quality deep groove ball bearings