The 3124/3841 movement consists of 364 parts and the operating frequency is 3Hz (21,600 bph). Again, I am happy to ask Audemars Piguet to develop a 4Hz chronograph movement for their sports watches. The power reserve is 50 hours and the movement uses a lovely gold automatic winding device-in this case, you will not see it because the back cover is strong. http://www.cheapestwrist.com