The green seal accompanying every Rolex watch is a symbol of its status as a Superlative Chronometer. This exclusive designation attests that it has successfully undergone a series of specific final controls by Rolex in its own laboratories according to its own criteria, in addition to the official COSC certification of its movement. This unique testing of the chronometric precision of the cased-up movement, as well as of the watch’s waterproofness, self-winding and power reserve, pushes back the boundaries of performance and makes Rolex the benchmark for excellence in mechanical watches. The green seal is coupled with a five-year guarantee which applies to all Rolex models.