Rolex
Rolex SA () is a Swiss luxury watchmaker. Originally founded as "Wilsdorf and Davis" by Hans Wilsdorf and Alfred Davis in London in 1905, the company registered "Rolex" as the brand name of its watches in 1908. In 1919, the company moved its base of operations to Geneva, Switzerland in order to avoid heavy taxation from a recovering post-war Britain, and "Montres Rolex S.A." was registered as the new company name by Hans Wilsdorf in Geneva in 1920. Since 1960, the company has been owned by the Hans Wilsdorf Foundation, a private family trust.
Hans Wilsdorf
In 1954 Rolex introduced another radical, avant-garde "tool watch" known as the GMT-Master. The GMT-Master had all the usual Rolex features including a watertight Oyster case, Perpetual movement, with luminous hands and markers, but added a 24 hour hand designed to keep time in a second timezone. Also, it features a rotatable 24 hour bezel which was luminous. The GMT-Master was originally designed for Pan American Airline Pilots and navigators as well as world travelers. 
Rolex introduced the Day-Date model in 1955, which was the first wrist watch to feature both a day-of-the-week aperture window, as well as a date aperture window. This made it easy for the wearer to know the exact day of the week as well as the date of the month at-a-glance. The Day-Date was somewhat similar to the Rolex Datejust at 36MM in diameter, but featured a slightly thicker case.
The Rolex Milgauss was introduced in 1956 with a Reference Number of 6541. This watch was designed with special anti-magnetic features for scientists who worked in research labs like CERN in Geneva, as well as for people who worked in power plants or medical facilities what could be affected by magnetism. The original Rolex Milgauss featured a second hand that looked like a lightning bolt, and in many ways looked like the Rolex Submariner.