The initial Royal Oak products were being equipped with 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 on the period with day indicator, and an All round height of 3.05mm. The calibre 2121 was also https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/