Calibre 3255 – the latest-generation Rolex movement.
With the calibre 3255, Rolex redefines a level of chronometric precision with criteria surpassing those of COSC (Contrôle Officiel Suisse des Chronomètres). The brand has developed a new method and high-technology equipment to test the precision of its superlative Chronometers, with tolerances that are twice as exacting as those for official certification and under conditions that simulate the movement of the watch on the wearer’s wrist, a system that reproduces the client’s daily life experiences. These exclusive chronometer tests complement the official COSC certification, to which all Rolex movements continue to be systematically submitted, and are not only carried out on the movements, but also on the assembled watches after they have been cased. Rolex has developed a specific test protocol based on a series of large-scale statistical studies to determine the actual conditions a watch really undergoes while worn on the wrist. As a result, the Rolex Chronometers equipped with movements tested according to this new method,demonstrate a precision on the wrist never achieved before.