STYLE 7700 EPDM PTFE Gasket is made of 100% Virgin PTFE with bonded with EPDM Rubber for high temperature resistance, high strength. This gasket has EPDM's advantage and also PTFE's advantage. Gasket has two sealing rings a primary and secondary. The gaskets are designed with dual, concentric, convex sealing rings to aid optimum sealing at lower bolt loads. It offers superior sealing for hazard media at low bolt torque. The unique inner PTFE sealing ring provided an additional sealing safety for both gases and liquids. Almost universal chemical resistance and non-contaminating for ultra-oure applications, along with the EPDM memory giving a long sealing life.