EPDM is a terpolymer (made up of three monomers) with ethylene, propylene and diene. This material possesses an excellent resistance to ozone, sunlight and weathering. It has very good flexibility at low temperature, good chemical resistance (many dilute acids and alkalis as well as polar solvents) and good electrical insulation property. Global O-Ring, Series: E70, 1.176 in ID, 0.07 in Cross Section, 025 Dash Number, 70 Shore A Durometer, -67 to 257 °F, EPDM, Black