Rolex GMT-Master 6542

Reference 6542 is the original GMT-Master, a professional tool watch developed with Pan American Airways and produced from approximately 1954 to 1959. Its most significant technical feature is its bi-directional bezel, which was initially fitted with an insert made of Bakelite. The 24-hour numerals on this insert were filled with the radioactive luminous material Radium, causing the bezel itself to be luminescent. Due to the material’s propensity to crack, these were soon recalled and replaced with anodized metal inserts, making original Bakelite examples exceptionally rare. The 38mm stainless steel Oyster case is characterized by the absence of crown guards, a feature specific to this first generation. The watch was powered by a succession of automatic movements, beginning with the Cal. 1036 and evolving to the Cal. 1065 and 1066.