In 1986, Patek Philippe introduced the reference 3970 alongside the rarer reference 3971. The 3971 carried very similar features as the 3970, though with a sapphire case back whereas the early 3970’s were fitted with a solid case back. The reference was the firm’s signature flagship model which was discontinued in 2004 and replaced by the last reference to be fitted with a Lemania based ebauche.

It is very important to note that the present watch belongs to the first series of the reference. The first series of the watch is identified by the transparent snap-on case back - an extremely rare feature, while the second series adopts a screw-down transparent case back. The first series is particularly rare for the reference, as scholars estimate that less than 10 pieces were made for the first series, in contrast to more than 100 examples being created for the second series.

The present example is a reference 3971 in yellow gold fitted with an attractive silvered dial with the day and date indication in Italian. Presented in overall excellent condition and further accompanied by a Patek Philippe extract from the archives, this present example is not one to miss for perpetual calendar chronograph connoisseurs.