O-Ring Viton AS568 Dash Number 389 Actual Width 0.210 In. Actual Inside Dia 19.955 In. Outside Dia 20.375 In. Cross Section Shape Round Durometer Rating Medium Hard Durometer 75 Shore A Nominal Width 3/16 In. Nominal Inside Dia 20 In. Nominal Outside Dia 20-3/8 In. Color Black Temp Range -15 Degrees to 400 Degrees F Meets/Exceeds SAE J200 ASTM D2000