O-Ring No Metal Detectable No X-Ray Detectable System of Measurement Inch Cross Section Shape Round O-Ring Material EPDM Durometer (Hardness) Rating Medium Hard Nominal Inside Dia 17 1/2 in Nominal Width 1/4 in Actual Inside Dia 17.455 in Actual Width 0.275 in Dash Number 464 Color Black Durometer 70 Shore A Meets/Exceeds ASTM D2000 SAE J200 Nominal Outside Dia 18 in Actual Outside Dia 18.025 in Temp Range -65 Degrees to 300 Degrees F FDA Approved No Package Quantity 2