During the 1940's, after submitting their requirements for military spec watches, the British MOD selected 12 respected Swiss manufacturers to produce watches for their personnel. This select group are now affectionately known as "The Dirty Dozen". Amongst the rarest and most respected is the IWC MK X. This historically important watch features IWC's manually wound calibre 83 movement, fixed strap bars, a sturdy water & dustproof case (engraved with the MOD issued 'Crow‘s foot' and correct 'M' issue letter), and black luminous dial, again sporting the Crow‘s foot government emblem.