Ca. Ø54mm, ca. 102g, 18K pink gold, case punch DMI 10632, extremely rare movement, full plate movement with chain/fusee, chronometer escapement, gear wheel with 10 teeth, jumping centre seconds, large, very slow oscillating balance, excellently preserved enamel dial, decentralised time display with real jumping seconds by a Breguet hand, fine pink gold arrow hands, indication of the French day of the week and the date, in excellent condition, intact, absolute rarity. The case punch DMI indicates Neuchatel. Pocket chronometers from this period with jumping seconds are extremely rare.