The 1st Royal Oak products were being fitted With all the calibre 2121 movement, which was dependant on the calibre 2120 developed by Audemars Piguet in 1967, the whole world’s thinnest self-winding movement of the period with day indication, and an All round top of 3.05mm. The calibre 2121 was https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/