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. 21 mm, Nominal Width 3 mm, Actual Inside Dia. 21 mm, Actual Width 3 mm, Color Black, Durometer 70 Shore A, Meets/Exceeds NBR 70, Nominal Outside Dia. 27 mm, Actual Outside Dia. 27 mm, No, Package Quantity 10