Audemars Piguet 2120/2808

The Audemars Piguet 2120/2808 is an automatic perpetual calendar movement based on the ultra-thin 2120 caliber. It displays the date, day, month, leap year, and astronomical moon phase, operating at 2.75 Hz with approximately 40 hours of power reserve. The 2808 module adds the perpetual calendar function to the 3.05mm-thick 2120 base, maintaining the profile required for thin Royal Oak cases. Production has ceased, though the movement saw use in Royal Oak references including the 5554 and 5588.