Daggerz™ brand Pro-Seal EPDM Bonded Washers are designed for applications that require a leakproof seal. The inside diameter of the NEOWG120916 rubber washer tightly seals to the screw. It features excellent ozone and weather-resistant elastomer that provides superior aging characteristics. This EPDM washer is heat resistant up to 350 degrees Fahrenheit. The galvanized steel backing material offers corrosion resistance and great strength characteristics.