... SERIES, HFL SERIES etc 2. Materials: GCr15, GCr15SiMn, G20Cr2Ni4A etc Ring and cages: Chrome bearing steel Balls: Chrome steel or carbon ... ; 6. Vibration Level: V1, V2, V3; 7. Packing: Bulk single color box/ tube/carton/pallet or customized. 8. Certification: ISO 9000/9001 ...