This is a British, WW2, Brass, Special Operations Executive and Commando Switch, No 2, Pressure, Mk 1 booby trap switch used for detonating explosives by means of a time pencil secured by a knurled nut. Booby trap mechanisms were developed by ‘Experimental Station 6’ which was a cover name for the SOE (Special Operations Executive) production facilities. The SOE ordered large numbers of switch through the British Security Coordination in the U.S. resulting in the America OSS adopting several British switches and developing others for their own use from British switches. This is a Switch No.2 Pressure, Mark 1 designed by Millis Jefferies. The switch consists of a brass body screwed to a brass fixing plate with pre drilled holes in it for fixing. The switch has a screwed nut for securing the primer pencil and a safety cap. The pressure plunger is retained to the body by a steel split pin. This is an early version of the switch, being made of brass as opposed to a one piece alloy casting. This is a rare piece of SOE and Commando equipment used WW2 and the price includes UK delivery. MISC 907