Audemars Piguet caliber AP 6401

Developed and manufactured in-house by Audemars Piguet, Calibre 6401 is a selfwinding integrated chronograph movement introduced for the updated Royal Oak Chronograph 38 collection. The movement operates at a frequency of 28,800 vibrations per hour (4 Hz) and comprises 350 components with 44 jewels. It measures 27 mm in diameter and has a thickness of 5.7 mm. The power reserve is approximately 55 hours. Calibre 6401 drives a display of hours, minutes, central seconds, date, and chronograph functions. The chronograph architecture is fully integrated rather than modular, marking a departure from the outsourced movements used in earlier 38 mm Royal Oak Chronograph references. The movement is finished to Audemars Piguet standards and is visible through a sapphire caseback.