O-Ring No Metal Detectable No X-Ray Detectable System of Measurement Metric Cross Section Shape Round O-Ring Material Kalrez 4079 Durometer (Hardness) Rating Medium Hard Nominal Inside Dia 15 mm Nominal Width 2.5 mm Actual Inside Dia 15 mm Actual Width 2.5 mm Color Black Durometer 75 Shore A Nominal Outside Dia 20 mm Actual Outside Dia 20 mm Temp Range 30 Degrees to 600 Degrees F FDA Approved No