Omega - A steel military '53 Fat Arrow' wristwatch, circa 1953, model 2777-1, serial number 13056214, signed circular black dial with white Arabic numerals and hands, centre sweep, tritium mark at 12H and 'fat' arrow at 6H, signed 17 jewel mechanical crown wind movement, calibre 283 under a metal cover, case 36mm diameter, verso engraved with pheon mark over 6645 101000 6B/542 283/53, fixed metal lugs to a black fabric double pass NATO style strap with steel fittings and pin buckle In June 1952 the British Air Ministry ordered 5900 wristwatches to very precise and demanding standards and Omega were approached to fulfil the order. The hour markers and hands were coated in radium for its luminous properties, and a thin arrow was added to the dial at 6H to indicate a military issue. However, the radioactive properties of the radium were considered too dangerous, so the watches were recalled and redialled using tritium. The 'T within a circle', marked at 12H, indicated a tritium dial, together with a 'fat' arrow which was applied to differentiate between the 'thin' arrow radium dials. The reissue to the RAF was in 1953, and as they were only produced for one year this watch is now often referred to as a '53 Omega'. Due to the relatively small numbers produced, 53 Omegas are becoming increasingly rare and are much sought after by military enthusiasts and collectors alike. The numbers on the case back refer to: 6645 - NATO stores code for a military watch 101000 - NATO watch model number 6B - RAF navigation equipment and accessories 542 - Pilot's wristwatch 283 - stores issue number 53 - year of issue