O-Ring No Metal Detectable No X-Ray Detectable System of Measurement Metric Cross Section Shape Round O-Ring Material Buna N Durometer (Hardness) Rating Medium Hard Nominal Inside Dia 30.7 mm Nominal Width 3.5 mm Actual Inside Dia 30.7 mm Actual Width 3.5 mm Color Black Durometer 70 Shore A Meets/Exceeds ASTM D2000 SAE J200 Nominal Outside Dia 37.7 mm Actual Outside Dia 37.7 mm Temp Range -40 Degrees to 250 Degrees F FDA Approved No Package Quantity 25