4 GHz/ 50 ohm (R141), 1.5 GHz/ 75 ohm (R142), 6 GHz/ 75 ohm HDTV (R142), 1.5 GHz/ 50 ohm SECurity (R140) / Bayonet coupling. The BNC was designed for military use and has gained wide acceptance in video & RF applications, and many t*es of test equipment.
