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 7 1/2 in Nominal Width 1/4 in Actual Inside Dia 7.475 in Actual Width 0.275 in Dash Number 443 Color Black Durometer 90 Shore A Meets/Exceeds ASTM D2000 NBR 90 Nominal Outside Dia 8 in Actual Outside Dia 8.025 in FDA Approved No Package Quantity 2