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 Medium Hard Nominal Inside Dia 4 in Nominal Width 1/8 in Actual Inside Dia 3.984 in Actual Width 0.139 in Dash Number 242 Color Black Durometer 70 Shore A Meets/Exceeds ASTM D2000 NBR 70 Nominal Outside Dia 4 1/4 in Actual Outside Dia 4.262 in FDA Approved No Package Quantity 25