3/32" Thick, Round Cross Section, Shore 70 - 80, 0 to 500°F Kalrez® is a perfluoroelastomer similar to PTFE and has a high resistance to chemicals, solvents and plasmas. It also maintains sealing force at high temperatures to reduce leakage.|Round cross-section shapes can be used in both static and dynamic applications. They are used as a mechanical seal or gasket and are seated in a groove and compressed during assembly between two or more parts.