Calibre 2236 Is fitted with a Syloxi hairspring that is produced by Rolex and patented. This silicon hairspring provides a patented geometry that ensures the calibre’s regularity in almost any placement. When approached with the correct way of thinking, that of getting exciting, the model exploits a niche pretty proficiently. https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/