The Precision of a Rolex Superlative Chronometer is of your buy of −two/+2 seconds on a daily basis – the speed deviation tolerated from the brand for any completed check out is appreciably scaled-down than that approved by COSC for official certification in the movement by itself. The Superlative Chronometer https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/