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 22 in Nominal Width 3/16 in Actual Inside Dia 21.955 in Actual Width 0.21 in Dash Number 391 Color Black Durometer 70 Shore A Meets/Exceeds ASTM D2000 SAE J200 Nominal Outside Dia 22 3/8 in Actual Outside Dia 22.375 in Temp Range -40 Degrees to 250 Degrees F FDA Approved No