Rolex GMT-MasterFasten your seatbelts for the story of the inimitable Rolex GMT-Master! As civil aviation took off after World War II, airlines began to fly over longer distances. As a result, pilots required accurate watches that could display multiple time zones simultaneously. In the early 1950s, Pan American Airways (Pan-Am) requested Rolex to develop a watch for this very purpose. The GMT-Master (‘GMT’ standing for ‘Greenwich Mean Time’) was introduced in 1954. It featured a 24-hour hand alongside the regular 12-hour hand. In combination with a bidirectional 24-hour bezel, this GMT hand could be used to read the home time zone while the 12-hour hand displayed the ‘local’ time.Despite its close links to aviation and its professional purpose, the Rolex GMT enjoys a fanbase far beyond the pilots it was originally intended for. Over the years Rolex has introduced many wonderful variations of the GMT: take your pick!Ref. 1675The ref. 1675 GMT-Master replaced the legendary ref. 6542 in 1959 and enjoyed an unusually long production run: over 20 years! The first 1675s received the well-known ‘pointed crown guards,’ which were replaced by regular rounded crown guards in 1964/1965. The dial of the 1675 also changed over time, starting with a glossy gilt chapter ring dial and ending with a matte radial dial (with significant variation in between, like the rare ‘exclamation mark,’ ‘underline’ and ‘Double-swiss’ dials).The 1675 was produced mostly in steel but was also available in 18k yellow gold or bicolor (steel and gold). The 1675 was the first Rolex ‘tool watch’ for which a factory-fitted jubilee bracelet was an option, starting in the early 1970s.