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 1/4 in Nominal Width 3/16 in Actual Inside Dia 3.2 in Actual Width 0.21 in Dash Number 339 Color Black Durometer 75 Shore A Nominal Outside Dia 3 5/8 in Actual Outside Dia 3.645 in Temp Range 30 Degrees to 600 Degrees F FDA Approved No