O-Ring Silicone AS568 Dash Number 438 Actual Width 0.275 In. Actual Inside Dia 6.225 In. Outside Dia 6.775 In. Cross Section Shape Round Durometer Rating Medium Hard Durometer 70 Shore A Nominal Width 1/4 In. Nominal Inside Dia 6-1/4 In. Nominal Outside Dia 6-3/4 In. Color Red Temp Range -65 Degrees to 450 Degrees F Meets/Exceeds SAE J200 ASTM D2000 FDA Approved