O-Ring No Metal Detectable No X-Ray Detectable System of Measurement Metric Cross Section Shape X O-Ring Material Buna N Durometer (Hardness) Rating Medium Hard Nominal Inside Dia 21 mm Nominal Width 2 mm Actual Inside Dia 21 mm Actual Width 2 mm Color Black Durometer 70 Shore A Nominal Outside Dia 25 mm Actual Outside Dia 25 mm Temp Range -40 Degrees to 250 Degrees F FDA Approved No Properties Resistant to Oils Resistant to Water Application Standard Package Quantity 5