Patek Philippe Perpetual Calendar Chronograph 3970EP

Patek Philippe Reference 3970EP | A platinum perpetual calendar chronograph wristwatch with moon phases, leap year and 24-hour indication | Circa 1996

Dial: black Calibre: cal. 27-70 manual winding, 24 jewels Movement number: 876'844 Case: platinum, screw-down sapphire crystal display case back Case number: 2'945'314 Closure: platinum Patek Philippe buckle Size: 36 mm diameter Signed: case, dial and movement Box: yes Papers: yes Accessories: Patek Philippe Certificate of Origin, platinum case back and presentation case Please note the leather strap derived from endangered species is for display purposes only and is not sold with the watch. The watch will be shipped with a Sotheby’s branded calf leather strap.Introduced in 1986, Patek Philippe’s reference 3970 was the third perpetual calendar chronograph produced in series, succeeding the iconic 1518 and 2499. It remained in production for nearly two decades, until 2004, and was offered in white, yellow, and pink gold, as well as platinum, with various dial configurations. Notably, the 3970 featured a classic 36mm case diameter, which is slightly smaller compared to its predecessor. This reference was also the first Patek Philippe perpetual calendar chronograph to include a leap year indicator. This upgrade was made possible by the use of the Lemania ébouche, instead of the Valjoux that was used for over fifty years by Patek. The production of the 3970 is divided in four series: 1986-1988: the first series of the 3970 featured a solid snap-on case back. 1987-1990: the second series introduced the reference 3970E, which featured an updated solid screw-down case back, with the suffix indicating étanche , or waterproof. 1989-1995: following the end of production of the 3971, the third series 3970 was delivered with two casebacks: one plain and one with a sapphire display back. 1994-2004: the fourth and last series was similar to the third series but with a new serial number range. During its evolution, the 3970 saw also some dial evolutions, most notably the change from baton indexes with leaf hands to lapidated indexes and pointing baton hands towards the end of the second series. The present example is a rare forth series platinum version with a non-diamond black dial and comes with its certificate of origin, second case back and presentation case