A pioneer in the world of watches since 1905 and a century-old model of chronochronology. Its original Oyster case was an important milestone in the history of diver's watches, with a screw-down bezel, caseback and crown in the middle case that greatly enhanced the watch's water-resistance. In the 20s of the last century, the British lady Mercedes successfully crossed the English Channel wearing a Rolex Oyster, and Rolex became famous overnight for its water-resistance. Today, the minimum water-resistance standard for Rolex Oysters is 100 metres. The deepest watch in the world is still Rolex, and the movement assembly is assembled by an authorized Rolex watchmaker. At present, Rolex produces about 450,000 watches per year, and has become one of the most famous watches in the market.