O-Ring No Metal Detectable No X-Ray Detectable System of Measurement Inch Cross Section Shape Round O-Ring Material EPDM Durometer (Hardness) Rating Medium Hard Nominal Inside Dia 4 1/8 in Nominal Width 1/8 in Actual Inside Dia 4.109 in Actual Width 0.139 in Dash Number 243 Color Black Durometer 70 Shore A Meets/Exceeds ASTM D2000 EPDM 70 Nominal Outside Dia 4 3/8 in Actual Outside Dia 4.387 in FDA Approved No Package Quantity 25