BREGUET ''TYPE XX MILITAIRE'' Ref 5101/54 Stainless steel chronograph watch, round case, unsigned matte black 2-counter dial with radium photoluminescent Arabic numerals, 30-minute chrono totalizer and small second hand at 3 and 9 o'clock. Non-graduated bidirectional fluted rotating bezel. Pump and pear-type pushers and winders. Plexiglas glass. Screw-down caseback, signed and numbered. Mechanical movement, column-wheel, with flyback function for the chrono, Valjoux 222 caliber. Leather strap with silvered metal buckle. Case back signed, numbered 7489, engraved with 12 end-of-warranty dates, from 1956 to 1983. Year of manufacture 1954. (scratches). Diameter: 38.5 mm. Breguet equipped the French Air Force and Naval Aviation from 1954 to 1979 with XX-type chronographs featuring the "return in flight" or "flyback" function found on the Valjoux 222. A first 2-counter version, marked "Breguet Type 20 5101/54", like our model, was produced, with the last digit representing the year of manufacture. Some 2,000 watches of this type were allocated. Bibliography: MONTRES MILITAIRES by Constantin Parvulesco; published by ETAI, pages 121 and 123.