The Precision of a Rolex Superlative Chronometer is with the purchase of −two/+two seconds a day – the speed deviation tolerated via the model for your concluded observe is significantly scaled-down than that approved by COSC for Formal certification of your motion by itself. The Superlative Chronometer standing is symbolized https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/