Rolex cal. 1520
The Rolex cal. 1520 is an in-house developed self-winding (automatic) movement used in earlier versions of the Rolex Submariner. It was introduced by Rolex in 1963 and has a frequency of 19,800 beats per hour (A/h) and 26 jewels. The movement has a Breguet hairspring and a KIF Ultraflex shock protection. The cal. 1520 has a central seconds function and a power reserve of 42 hours.
