Ethylene Propylene Terpolymer, 56-65 °IRHD. Terpolymer of ethylene, propylene and diene monomers. To meet Aerospace Specification DTD5597A Grade 60.Applications: For sealing applications where good fluid resistance and low compression set are of prime importance. For continuous and/or intermittent use in contact with phosphate ester or silicone hydraulic fluids within the temperature ranges as quoted. Suitable for applications in contact with air, this material has excellent resistance to ozone. Unsuitable for use in contact with fuels, mineral oil based and diester oils and silicate fluids or greases derived from these.