O-Ring No Metal Detectable No X-Ray Detectable System of Measurement Metric Cross Section Shape Round O-Ring Material Viton Durometer (Hardness) Rating Medium Hard Nominal Inside Dia 30 mm Nominal Width 4 mm Actual Inside Dia 30 mm Actual Width 4 mm Color Black Durometer 75 Shore A Meets/Exceeds FKM 75 Nominal Outside Dia 38 mm Actual Outside Dia 38 mm FDA Approved No Package Quantity 10