Audemars Piguet 6401

The caliber 6401 is an automatic in-house movement developed by Audemars Piguet, measuring 27 mm in diameter and 5.7 mm in height. It operates at a frequency of 28,800 vibrations per hour and offers a power reserve of 55 hours, with an automatic bidirectional winding mechanism. The movement features a column wheel construction with small seconds, date and chronograph complications, and is used in the models 26430 and 26450.