O-Ring No Metal Detectable No X-Ray Detectable System of Measurement Inch Cross Section Shape Round O-Ring Material Silicone Durometer (Hardness) Rating Medium Hard Nominal Inside Dia 19 in Nominal Width 3/16 in Actual Inside Dia 18.955 in Actual Width 0.21 in Dash Number 388 Color Red Durometer 70 Shore A Meets/Exceeds ASTM D2000 -VQM 70 FDA 21 CFR 177.2600 Nominal Outside Dia 19 3/8 in Actual Outside Dia 19.375 in Temp Range -65 Degrees to +400 Degrees F