O-Ring No Metal Detectable No X-Ray Detectable System of Measurement Inch Cross Section Shape Round O-Ring Material HNBR Durometer (Hardness) Rating Medium Hard Nominal Inside Dia 4 7/8 in Nominal Width 3/16 in Actual Inside Dia 4.8 in Actual Width 0.21 in Dash Number 352 Color Black Durometer 80 Shore A Nominal Outside Dia 5 1/4 in Actual Outside Dia 5.27 in Temp Range -55 to 300 Degrees F FDA Approved No