O-Ring No Metal Detectable No X-Ray Detectable System of Measurement Inch Cross Section Shape Round O-Ring Material Kalrez 4079 Durometer (Hardness) Rating Medium Hard Nominal Inside Dia 3 1/8 in Nominal Width 3/16 in Actual Inside Dia 3.1 in Actual Width 0.21 in Dash Number 338 Color Black Durometer 75 Shore A Nominal Outside Dia 3 1/2 in Actual Outside Dia 3.52 in Temp Range 30 Degrees to 600 Degrees F FDA Approved No