The first high-frequency, automatic chronograph was also the first chronograph to feature a running seconds hand and measured in at a slim 6.5mm thick. Much thinner than the traditional chronographs at the time. The first watch to feature the new movement was the El Primero reference A384 in March 1969.
In the early 1920s, the world was a living laboratory for Rolex...In the 1930s, Rolex would approach one of the world’s fastest drivers, Sir Malcolm Campbell, and offer to assist him in his quest for speed.
Ah, Rolex. That "Paragon of Animals." Perhaps the most recognizable watch brand in the world--known to collectors and laymen alike. However, the ubiquity of Rolex does not mean there are not further depths to plumb. While the terms Datejust, Submariner, and Sea-dweller roll easily off the tongue of watch enthusiasts everywhere, lesser know gems abound.