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 8 3/4 in Nominal Width 3/16 in Actual Inside Dia 8.725 in Actual Width 0.21 in Dash Number 372 Color Black Durometer 90 Shore A Meets/Exceeds ASTM D2000 NBR 90 Nominal Outside Dia 9 1/8 in Actual Outside Dia 9.145 in FDA Approved No Package Quantity 2