The Precision of the Rolex Superlative Chronometer is of the get of −two/+2 seconds on a daily basis – the speed deviation tolerated because of the model for your finished check out is appreciably scaled-down than that approved by COSC for Formal certification in the motion alone. The Superlative Chronometer https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/