Patek Philippe’s reference 3970 evolved from a line of important and iconic perpetual calendar chronograph wristwatches, which first began in 1941 with the reference 1518. Launched in 1986 as the replacement for the reference 2499, the 3970 featured a heavily modified Lemania-based movement over the Valjoux-based calibers used in the earlier 1518 and 2499 references. The 36 mm case had a decidedly modern appeal. Over its 19-years of production, the 3970 underwent three significant modifications. The first series featured a snap on case back, with applied gold baton indexes and feuille hands, and the subdials are slightly off colour. The second series featured a screw-down, solid case back, gold applied baton indexes and feuille hands, registers now match the dial. The third series featured a sapphire display back with a screw-down solid case back, lapidated indexes and baton hands, printing on dial is darker, and the silver brighter. Manufactured in 1991, the present lot is a hardly ever seen second series example in platinum, featuring coveted feuille hands and rectangular indexes. Fresh to the auction market and complete with its original certificate of origin and presentation box, the present lot is a superb example of Patek Philippe’s famous reference 3970, and amongst the finest and most prestigious examples one could hope to acquire.