bearing 1.High precision,long life,low noise 2.6000 6200 6300 6800series 3.Very smooth hand feeling 4.high-end technology auto ... , 7000A, 7000B, DB, DF, ETC. ISO 9001-2000 certificated Material: bearing steel, carbon steel, stainless steel. Etc. Precision: P0 P5 P6 ... , 68series, 160series etc. for more information, please contact us ball bearing