... , like canteen, water dispenser and so on.1. All rubber products are made according to international standard: ISO 3601, AS 568A, DIN3771 ... your option, including Buna-N (NBR), HNBR, VITON, Silicone, FluoroSilicone, EPDM, Teflon, Natural Rubber, BUTYL, SBR, Neoprene, HYPALON, etc.Our Company is ... DVGW certification and British WRAS (WRC) drinking water standard certification. Silicone Rubber O-Ring