The movements of its Oyster Perpetual and Cellini watches are certified by COSC, then tested in-house for their precision, performance and reliability. The Superlative Chronometer certification, symbolized by the green seal, confirms that each watch has successfully undergone tests conducted by Rolex in its own laboratories according to its own criteria. These are periodically validated by an independent external organization. The word “Perpetual” is inscribed on every Rolex Oyster watch. But more than just a word on a dial, it is a philosophy that embodies the company’s vision and values. Hans Wilsdorf, the founder of the company, instilled a notion of perpetual excellence that would drive the company forward. This led Rolex to pioneer the development of the wristwatch and numerous major watchmaking innovations, such as the Oyster, the first waterproof wristwatch, launched in 1926, and the Perpetual rotor self-winding mechanism, invented in 1931. In the course of its history, Rolex has registered over 500 patents. At its four sites in Switzerland, the brand designs, develops and produces the majority of its watch components, from the casting of the gold alloys to the machining, crafting, assembly and finishing of the movement, case, dial and bracelet. Furthermore, the brand is actively involved in supporting the arts and culture, sport and exploration, as well as those who are devising solutions to preserve the planet.