The “Dirty Dozen” is the collectors’ name for the W.W.W. wristwatches that twelve Swiss manufacturers supplied to the British Army in 1945 under Ministry of Defence contracts. W.W.W. stands for Watch, Wrist, Waterproof. All followed the same specification: a black dial with luminous Arabic numerals, luminous hands, a subsidiary seconds dial at 6 o’clock and the military broad arrow, in a steel or chrome-plated case of about 35 to 38 mm with fixed bars and the “W.W.W.” and broad arrow engraving plus a military number on the back. The movements were hand-wound and had to be regulated to chronometer standards, with the cases waterproof and the watches shock resistant. The Omega uses the 15-jewel calibre 30T2 and the IWC Mark X the calibre 83.

The twelve makers were Buren, Cyma, Eterna, Grana, IWC, Jaeger-LeCoultre, Lemania, Longines, Omega, Record, Timor and Vertex, the last a British firm with production in Switzerland. The first batch shipped in March 1945 and the last at the end of that year, with total output estimated at around 145,000 to 150,000 watches. They served across British stations and in later conflicts from Suez to the Falklands, and some went to the Netherlands Indies and the Kenyan and Rhodesian armies. Ministry workshops often replaced dials, hands and backs, so original condition is rare.

Collectors prize the Dirty Dozen as a set, and assembling all twelve is difficult because the makers delivered very different quantities. Grana is the rarest, with an estimated 1,000 to 1,500 made, and one sold at Bonhams in November 2022 for £31,800. The Omega is the most common, while the IWC, Longines and Jaeger-LeCoultre fetch the most; an IWC Mark X sold at Bonhams in 2019 for £2,500, and a complete worn set made €26,300 at Uhren-Muser in November 2025. The W.W.W. watches are no longer produced; the contracts ended with the 1945 deliveries.