O-Ring No Metal Detectable No X-Ray Detectable System of Measurement Metric Cross Section Shape Round O-Ring Material Buna N Durometer (Hardness) Rating Medium Hard Nominal Inside Dia 2.5 mm Nominal Width 1 mm Actual Inside Dia 2.5 mm Actual Width 1 mm Color Black Durometer 70 Shore A Nominal Outside Dia 4.5 mm Actual Outside Dia 4.5 mm Temp Range -40 Degrees to 250 Degrees F FDA Approved No Properties Resistant to Oils Resistant to Water Application Standard