O-Ring, No Metal Detectable, No X-Ray Detectable, System of Measurement Metric, Cross Section Shape Round, O-Ring Material Viton, Durometer (Hardness) Rating Medium Hard, Nominal Inside Dia. 4 mm, Nominal Width 2 mm, Actual Inside Dia. 4 mm, Actual Width 2 mm, Color Black, Durometer 75 Shore A, Nominal Outside Dia. 8 mm, Actual Outside Dia. 8 mm, Temp. Range -15 Degrees to 400 Degrees F, FDA Approved No