“La Grande Sonnerie” is a world first inasmuch as it is the first wristwatch ever to hold a miniaturized 51-jewel movement comprising something over 410 parts. Its dimensions (28.6 x 5.2 mm) constitute a very impressive feat of micro-engineering. A three-position slide bolt at 2 o’clock on the case flank serves to trigger the grand strike mechanism that sounds hours and quarters «en passant», the lesser strike that sounds hours only «en passant» and to stop the mechanism. A pushpiece at 10 o’clock will also trigger the hour and quarter strike on demand. The grand strike possesses a 10-hour power reserve, the lesser strike a 32-hour reserve while the watch will run 48 hours without rewinding. The strike mechanism is designed to avoid miscounting and includes a silent regulator that muffles mechanical noises during the strike. The strike mechamisms and movement are rewound in the usual way by the crown.