The Precision of a Rolex Superlative Chronometer is from the purchase of −2/+2 seconds a day – the speed deviation tolerated from the brand name for the completed watch is drastically smaller than that approved by COSC for Formal certification on the movement alone. The Superlative Chronometer standing is symbolized https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/