O-Ring No Metal Detectable No X-Ray Detectable System of Measurement Inch Cross Section Shape Round O-Ring Material FEP with Viton Core Durometer (Hardness) Rating Very Hard Nominal Inside Dia 2 5/8 in Nominal Width 1/8 in Actual Inside Dia 2.609 in Actual Width 0.139 in Dash Number 231 Color Clear with Black Core Durometer 90 Shore A Meets/Exceeds ASTM D2116 Nominal Outside Dia 2 7/8 in Actual Outside Dia 2.887 in Temp Range -15 Degrees to 400 Degrees F FDA Approved Yes