O-Ring No Metal Detectable No X-Ray Detectable System of Measurement Inch Cross Section Shape Round O-Ring Material Viton Durometer (Hardness) Rating Very Hard Actual Inside Dia 0.644 in Actual Width 0.087 in Dash Number 908 Color Black Durometer 90 Shore A Meets/Exceeds ASTM D2000 SAE J200 Nominal Outside Dia 1/2 in Actual Outside Dia 0.818 in Temp Range -15 Degrees to 400 Degrees F FDA Approved No Package Quantity 25