... Phosphated, Nitrided,Chrome plated 3.ISO9002, QS9000, TS16949 engine piston ring set OEM manufacturer 1.Dia from 90mm ... EL100, EB300, EB400, EV700, DM100, DQ100, EC100, YJ39, K13C, V21C etc.-------------------Guangzhou Dwit Auto Parts Co., Ltd. DWIT History ... Korean & Japanese etc.Caterpillar, Cummins, Perkins, Komatsu, Mitsubishi, Nissan, Hino, Isuzu, Toyota, Daewoo, Hyundai, Kia, Volvo, Benz, MAN, DAF ...