Very Rare WW2 SOE isued No9 Mk1 switch container

Very Rare WW2 SOE isued No9 Mk1 switch container

Image Gallery:

Product Information

This is an exceptionally rare, January 1945 dated and issued tin which would have contained ten No9 Mk1 “L-Delay” switches, as produced by the highly secretive research and development organisation MD1, colloquially known as “Chruchill’s Toybox”.

Developed in 1940 by former “Armchair Science” editor Stuart Macrae and in full production by October of that year, the No9 Mk1 switch saw successful use in Special Operations Executive (SOE) and resistance hands in waging guerrilla warfare behind enemy lines throughout the War. Using an ingenious lead element as a timer (hence the name L-Delay, L denoting lead), a range of switches was available for differing time delays from 1 hour to 28 days. Once used, the tins were discarded along with the enclosed instructions to avoid letting vital intelligence fall into enemy hands. Remarkably, not only has the tin survived, but it contains its original paperwork, including card packing material, instructions for use and packing slip with Lot number G66 matched to the tin. The instructions are clearly marked “NOT TO BE PUBLISHED” with a warning not to allow any information to be given to the Press or any person not in an official position within His Majesty’s Service, further adding to the rarity of this intriguing survivor.

Only recently discovered, sealed and with a full compliment of live No9 Mk1 switches - the Explosive Ordnance Disposal chaps dealt with them in a fittingly explosive end, leaving the container with the owner.  We’ve never seen another – this tin will make a staggeringly rare addition to any collection.



To order Call 01547 529093 or 05603 416575 or email

Product Code: 9R4