Breitling - A steel 'Chronomat Longitude' wristwatch

vintage unknown, model number A20048, serial number 5702, circular black dial with Arabic numerals, white hands, black GMT hand, centre chronograph sweep, subsidiary dials for running seconds at 9H, minutes at 12H and hours at 6H and date window at 3H, outer compass track with white Arabic markers, tandem signed 25 jewel mechanical automatic chronometer rated ETA movement calibre 7750 with start/stop and reset pushers above and below the crown, case, 40mm diameter, unidirectional rotating bezel with baton and Arabic markers between the four rider tabs, to a brown strap with pin buckle, presented in the outer card box