The first Royal Oak versions have been equipped with the calibre 2121 motion, which was dependant on the calibre 2120 made by Audemars Piguet in 1967, the entire world’s thinnest self-winding motion on the era with date sign, and an All round top of 3.05mm. The calibre 2121 was also https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/