Rubber O-Ring Oil Seal, Gasket, U-Ring, Quad-Ring, Glyd-Ring, Step Seal, Mechanical Seal, Extrusion Seals, Rotating Seals 1. All rubber products are made ... -N (NBR), HNBR, VITON, Silicone, FluoroSilicone, EPDM, Teflon, Natural Rubber, BUTYL, SBR, Neoprene, HYPALON, etc. Our Company is committed to ... American NSF, Germany DVGW certification and British WRAS (WRC) drinking water standard certification.