Standard Gaskets for metallic couplings are BUNA Nitrile. For Polypropylene Snaplock couplings, standard gaskets are Ribbed Santoprene. Various materials are available including, Buna, EPDM, Viton, Teflon Buna, Teflon Viton, and Neoprene. FEP/Silicone fully encapsulated seals also available for hazardous chemicals.