Santoprene NSF-61 grade is a Thermoplastic Elastomer (TPE) made from a cross link mixture of EPDM rubber and Polypropylene. This combination offers excellent flexibility and durability that are consistent with natural rubber. It is environmentally age resistant in both hot and cold extreme environments. Its excellent electrical properties make Santoprene the preferred sealing and isolating material over Neoprene and EPDM rubber. Santoprene NSF-61 materials are certified to meet the required specification for applications concerning potable water.