Dial, case and movement signed. DIAM. 40 mm. THICKNESS 15 mm. The final version of the famed BREGUET TYPE XX CAL. 726 wristwatch, prior to the 1994 re-release, were available in two versions; those featuring a two register- 60 minute counter using the Valjoux Cal. 725 movement, or a 3 register dial with the addition of a 12-hour counter using the Cal. 726 movement; the 726 was the fly-back version of the Cal.72 found in the Rolex Daytona model. Both movements were fitted within a slightly larger 40.6mm. diameter steel case with matt black rotating bezels. Research would suggest examples of the more complex versions with 12-hour registers were designated by a letter B in front of the 5 digit case number. Although possibly very early production models were assigned for military use, the final version of Breguet aeronautic 'military' chronograph was only available for the civilian market exclusively from the Paris boutique, albeit in relatively limited numbers, from the early 1970's until the 1980's. Apparently only 1,400 Valjoux Cal.725 movements were designated for use by Breguet, with presumably a mere 10 percent of that figure representing the number of three-register Cal. 726 movements ordered.