Calibre 2236 Is fitted with a Syloxi hairspring that is made by Rolex and patented. This silicon hairspring contains a patented geometry that ensures the calibre’s regularity in any situation. The 3rd big action transpired while in the early 1900’s. The form on the timekeeping equipment adjusted in favor on https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/