O-Ring No Metal Detectable No X-Ray Detectable System of Measurement Inch Cross Section Shape Round O-Ring Material Buna N Durometer (Hardness) Rating Medium Hard Nominal Inside Dia 3/4 in Nominal Width 1/16 in Actual Inside Dia 0.739 in Actual Width 0.07 in Dash Number 018 Color Black Durometer 70 Shore A Meets/Exceeds 21CFR177.2600 ASTM D2000 NSF Standard 61 SAE J200 Nominal Outside Dia 7/8 in Actual Outside Dia 0.879 in Temp Range -40 Degrees to 250 Degrees F