... (FKM), viton DuPont & Dow elastomers, neoprene, HNBR, NBR + PVC, natural rubber, SBR, IR, IIR (butylrubber), CR (neoprene), SBR, AU, ACM, CO ... , etc. NSF-61 approved material, meets drinking water system requirements2) All manufacturing processes confirm to the ISO-90003 ... are accepted 7) Available in various sizes and colors Extension pipe rubber