... 3.high quality and reasonable price O-ring 1. Offer a wide range of O-ring in all standard size and a ... lot of special size. 2. All o-ring are made according to international standard: ISO 3601, AS 568A ... , including Buna-N (NBR), HNBR, VITON, Silicone, FluoroSilicone, EPDM, Teflon, Natural Rubber, BUTYL, SBR, Neoprene, HYPALON, etc. o ...