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 3 in Nominal Width 3/16 in Actual Inside Dia 2.9 in Actual Width 0.21 in Dash Number 337 Color Black Durometer 90 Shore A Nominal Outside Dia 3 3/8 in Actual Outside Dia 3.395 in Temp Range -55 to 300 Degrees F FDA Approved No Properties Resistant to Chemicals Resistant to Oils Resistant to Water