This is a highly collectible Patek Philippe Travel Time Ref 2597 in yellow gold from the 1960's. In 1959, Patek Philippe patented the Time Zone Watch feature which is used in this 2597 reference. The case is a classic Calatrava 570 case with a travel time movement inside. The 2 push buttons on the left side of the case operate the feature. The top button advancing the hour hand forward and the bottom button moving it back, to accomodate the movement of the wearer between time zones. This is quite a mechanical innovation for the time. These watches are extremely rare, especially in original condition as this one is.
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