O-Ring, No Metal Detectable, No X-Ray Detectable, System of Measurement Inch, Cross Section Shape Round, O-Ring Material Buna N, Durometer (Hardness) Rating Very Hard, Nominal Inside Dia. 9/16 in, Nominal Width 3/16 in, Actual Inside Dia. 0.537 in, Actual Width 0.21 in, Dash Number 311, Color Black, Durometer 90 Shore A, Meets/Exceeds ASTM D2000, NBR 90, Nominal Outside Dia. 15/16 in, Actual Outside Dia. 0.957 in, No, Package Quantity 10