Description
TYPE 671 (NATO) JACK PLUGS
An old design of 4-pole jack plug still used on a number of intercom systems, commonly known as a “NATO” plug. BPO type 671. NATO stock code 5935-99-946-6652. Similar to the old British Post Office telephone plug type 420, but not compatible. Shaft diameter 7.5mm.
Standard wiring convention: Tip/Ring 1 – mic, Ring 2/Ring 3 – ear loudspeakers (Ring 1 is adjacent to tip).