Calibre 2236 Is fitted by using a Syloxi hairspring that is made by Rolex and patented. This silicon hairspring has a patented geometry that ensures the calibre’s regularity in any placement. Ming didn't just slap the movement in a case and contact it per day. The movements were being overhauled, https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/