O-Ring No Metal Detectable No X-Ray Detectable System of Measurement Inch Cross Section Shape Round O-Ring Material HNBR Durometer (Hardness) Rating Hard Nominal Inside Dia 7/16 in Nominal Width 1/16 in Actual Inside Dia 0.4 in Actual Width 0.07 in Dash Number 013 Color Black Durometer 90 Shore A Nominal Outside Dia 9/16 in Actual Outside Dia 0.566 in Temp Range -55 to 300 Degrees F FDA Approved No Properties Resistant to Chemicals Resistant to Oils Resistant to Water