Introduction and Launch: The Rolex calibre 1520, introduced in 1963, was a simplified verision of the calibre 1530, and is a self-winding movement, used in the Rolex Air-King and Submariner. While the “Superlative Chronometer Officially Certified” text on Rolex dials signifies precision and prestige, many of Rolex’s earlier watches were not chronometer-certified. Some collectors even appreciate the cleaner aesthetic of non-COSC dials with less text.
