6 mm, Actual Outside Dia.
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. Viton O-Ring, 1mm Wide 4mm ID, PK50 Range -15 Degrees to 400 Degrees F, FDA Approved No 4 mm, Actual Width 1 mm, Color Black, Durometer 75 Shore A, Nominal Outside Dia. 4 mm, Nominal Width 1 mm, Actual Inside Dia..