O-Ring No Metal Detectable No X-Ray Detectable System of Measurement Inch Cross Section Shape Round O-Ring Material Neoprene Durometer (Hardness) Rating Medium Hard Nominal Inside Dia 3 1/2 in Nominal Width 1/8 in Actual Inside Dia 3.484 in Actual Width 0.139 in Dash Number 238 Color Black Durometer 70 Shore A Meets/Exceeds ASTM D2000 SAE J200 Nominal Outside Dia 3 3/4 in Actual Outside Dia 3.762 in Temp Range -40 Degrees to 225 Degrees F FDA Approved No