3/16" Thick, Round Cross Section, Shore 70, -65 to 300°F EPR is an ethylene-propylene copolymer that offers excellent resistance to fluids used in commercial aircraft hydraulic systems. They also are recommended for hot water, steam, and phosphate ester-type hydraulic fluids. Not recommended for petroleum fluids or diester lubricants.|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.