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 1/4 in Nominal Width 1/8 in Actual Inside Dia 9.234 in Actual Width 0.139 in Dash Number 271 Color Black Durometer 90 Shore A Meets/Exceeds ASTM D2000 NBR 90 Nominal Outside Dia 9 1/2 in Actual Outside Dia 9.512 in FDA Approved No Package Quantity 2