In 1954 Rolex presented the first GMT-Master ref. 6542, which indicates the time in two chosen time zones simultaneously via a 24-hours-hand and rotating bezel. Interestingly, the GMT-Master name was only registered one year later in April 1955. Only five years after its introduction, the reference 6542 was being replaced by the reference 1675. In 1983, Rolex introduced the GMT Master II which can display three different time zones through a now independent 24-hours-hand.
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