The Precision of the Rolex Superlative Chronometer is in the order of −2/+2 seconds daily – the speed deviation tolerated with the manufacturer for any completed look at is substantially scaled-down than that recognized by COSC for Formal certification of the movement on your own. The Superlative Chronometer status is https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/