A very good example of a GMT-Master II Coke with a pleasing and even layer of wear appropriate for an unpolished watch of this age. First released in 1954, the GMT-Master was a joint effort by the watchmakers at Rolex and pilots at Pan American Airways. This resulted in the ref. 6542, which utilised the base movement and case from the Turn-o-Graph ref. 6202 (which developed into the Submariner) and modified it to include the now-famous 24-hour hand and two-colour bezel. In 1982, the first GMT-Master II was released. This was a greatly improved version, which allowed the 12-hour hand to be independently set in one-hour increments forwards and backwards. As a result, this allowed for an extra timezone to be tracked by the user.