The Precision of a Rolex Superlative Chronometer is of the order of −two/+two seconds daily – the rate deviation tolerated through the brand name for just a completed watch is noticeably scaled-down than that approved by COSC for Formal certification in the movement alone. The Superlative Chronometer position is symbolized https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/