In 1953, Pan Am executives asked Rolex-founder Hans Wilsdorf if he could develop a watch that could show two timezones at once. Always focused on innovation, Wilsdorf accepted the challenge and soon after penned down the first ideas of what would become the GMT-Master. Like nearly all the watches in the Professional-line of Rolex, was also the GMT-Master immediately embraced by the public. Demand was strong, and the GMT-Master would become one of the pillars of the Rolex collection. In 1982, Rolex debuted the GMT-Master II. The main difference between this model and the GMT-Master I was that you could pull out the crown and set the hand for the second-timezone individually.