Calibre 2236 Is fitted that has a Syloxi hairspring that is produced by Rolex and patented. This silicon hairspring features a patented geometry that makes sure the calibre’s regularity in any position. Tissot traces its lengthy historical past again to 1853, when it had been Started by the father-son crew https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/