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 4 1/4 in Nominal Width 3/16 in Actual Inside Dia 4.2 in Actual Width 0.21 in Dash Number 347 Color Black Durometer 90 Shore A Nominal Outside Dia 4 5/8 in Actual Outside Dia 4.645 in Temp Range -55 to 300 Degrees F FDA Approved No Properties Resistant to Chemicals Resistant to Oils Resistant to Water