Calibre 2236 Is fitted by using a Syloxi hairspring that is made by Rolex and patented. This silicon hairspring provides a patented geometry that guarantees the calibre’s regularity in almost any posture. Coupled with his colleague Thomas Earnshaw, the pair would create simplified and functional maritime chronometers. General public institutions https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/