Rolex 2135

History: The Calibre 2135 replaced the older Calibre 2035 that had found success inside the Ladies Oyster Perpetual, as well as the ladies and midsize Datejust. When first introduced, 2135, the demonstrated the highest first time pass rate of any movement tested by the Official Swiss Chronometer Testing Institute. At just 20mm in diameter and 5.83mm in height, the 29-jewel calibers still manage to provide a 42-hour power reserve. The automatic, self-winding movements beat at 28,800vph, the standard frequency of all modern Rolexes that provides the characteristic eight ticks a second smooth sweep of the seconds hand, as well as giving an increased shock protection.

There is a hacking capability with this movement.

Manufacturer: Rolex SA (/ˈroʊlɛks/) is a Swiss luxury watchmaker. The company and its subsidiary Montres Tudor SA design, manufacture, distribute and service wristwatches sold under the Rolex and Tudor brands. Founded by Hans Wilsdorf and Alfred Davis in London, England in 1905 as Wilsdorf and Davis, Rolex moved its base of operations to Geneva, Switzerland in 1919. Forbes ranked Rolex 64th on its 2016 list of the world's most powerful global brands.[Rolex is the largest single high end watch brand. The company is owned by the Hans Wilsdorf Foundation, a private family trust.

Alfred Davis and his brother-in-law Hans Wilsdorf founded Wilsdorf and Davis, the company that would eventually become Rolex SA, in London, England in 1905. Wilsdorf and Davis' main commercial activity at the time involved importing Hermann Aegler's Swiss movements to England and placing them in high-quality watch cases made by Dennison and others. These early wristwatches were sold to jewellers, who then put their own names on the dial. The earliest watches from Wilsdorf and Davis were usually hallmarked "W&D" inside the caseback.

From Wikipedia