The Precision of a Rolex Superlative Chronometer is of your purchase of −two/+two seconds a day – the speed deviation tolerated from the manufacturer for any concluded enjoy is noticeably scaled-down than that approved by COSC for official certification with the movement by itself. The Superlative Chronometer standing is symbolized https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/