This is a rare example of the coveted second series of the Patek Philippe Perpetual Calendar reference 3970* in rose gold. The combination of complications, which has come to be synonymous with Patek Phillipe, is presented in a water-resistant case with a screwed down caseback crafted from rose gold and paired with a silvered dial built on a solid gold base. It is replete with details typical of the first and second series, including attractive feuille-style hands and simple, faceted hour markers. It is powered by the manually wound calibre CH 27-70 Q, based on the Lemania 2320 that is topped with a perpetual calendar module and finely finished to warrant its Geneva seal. More than 40 years on from the release of the original perpetual calendar chronograph, the reference 1518, Patek Philippe released the reference 3970 in 1986. The 3970, which followed another iconic reference, the 2499, and was produced from 1986 to 2004 in four successive series. In many ways, the 3970 marked the historic brand’s first step in the modern era, with increased production capabilities. While around 100 pieces of the first series were produced in 1986, the second series was created for a considerably longer period between 1986 and 1991 with around 650 pieces produced in this era benefitting from several refinements. Unlike the first series, which was produced only in yellow gold, the second series was made in yellow, rose and white gold, as well as in platinum. While the white metal cases remain the most elusive, examples from the second series in rose gold are also hard to come by and consequently highly coveted. Where the first series had snap-on casebacks, the second series marks the introduction of a solid screw-down style variant. This explains the letter "E" in the reference number – for ‘étanche’, or waterproof case. Another detail of the first series, the darker shading of the subsidiary registers compared to the overall hue of the dial, is also lost in the second. Crucially, the second series retained several attractive traits of the first. This included the feuille-style hands reminiscent of those found on the 1518 and 2499. From around 1990 onwards, the reference 3970 gradually adopted more contemporary design details such baton hands and more pointed and faceted hour markers. This example, which retailed in July 1989, was produced right in the middle of the series. The 36mm case is perfectly balanced, larger than the 1518 but smaller than the 2499. Its concave bezel meets a rounded midcase that is home to the rounded chronograph pushers, Calatrava-signed crown as well as the four correctors for the perpetual calendar and moonphase displays. On the movement side, the circular brushed, closed caseback is screwed down. The robust, sculptural lugs feature a stepped facet. They curve down. The top left and bottom right lugs feature crisp precious metal hallmarks. In rose gold, these details are rendered a distinct warmth and softness that is very attractive. The 19mm lugs are furnished with a fresh, large-grained black leather strap secured by a rose gold pin buckle. In addition to it, this set also includes a signed deployant clasp. Within the context of the case metal, the silver colour of the dial, with a solid gold base, offers a degree of contrast. The rose gold feuille hands are paired with pointed baton indices also crafted from the same metal. Hash-style minutes chapters lie in between the markers. The day and month indications are expressed through twin window apertures in the northern half of the dial. Each of the three subsidiary registers expresses two units of time. They are graduated with the sort of typewriter font that is typical of later second series examples. The register at 9 features running seconds as well as a small 24-hour indication; the one at 3 shows 30 elapsed minutes and is also home to the leap year indication. The register at 6 expresses the date as well as the moonphase cycle. This was also one of the last examples of the 3970E to obscure the manually wound calibre CH 27-70 Q, based on the Lemania 2320 ébauche. Extensively modified and topped with a perpetual calendar module, the movement is finely decorated by hand to warrant its Geneva seal. The single barrel offers 60 hours of reserve. This example, with its unpolished rose gold case, retains all of its original charm. It comes with two sets of service papers from Patek Philippe in addition to the archive extract and original box. The second series of the reference 3970 features many details that are coveted and a case that was at the time still finished by hand. It is testament to the longevity of fine, considered design and details. Closer look Brand: Patek Philippe Model: Chronograph ref. 3970E Movement: manual-winding calibre 27-70Q Functions: perpetual calendar: leap year indicator, month, date, day, moonphase, day/night indicator, hours, minutes, centre seconds, chronograph Features: solid caseback Case material: rose gold Case diameter: 36mm Case thickness: 12.9mm Lug-to-lug: 43.2mm Crystal: sapphire front Strap: grained leather strap from our own collection, Patek Philippe matt black alligator strap, Patek Philippe gloss black alligator strap, Patek Philippe rose gold deployant buckle, Patek Philippe rose gold pin buckle Lug width: 19 x 14mm Year: 1989 Accompanying materials: Patek Philippe wooden box, archive extract (signed, stamped & dated), service letter (dated 2020), service invoice (from 2020), pin pusher Condition This Patek Philippe Chronograph is in excellent overall condition. The case and lugs remain unpolished and show virtually no signs of wear, only very light superficial marks on the very surface of the material. The dial, hands, and movement are free of imperfections and have been well preserved. All hallmarks and engravings are well defined. Warranty The watch comes with a two-year, limited warranty from A Collected Man, alongside a lifetime guarantee of authenticity.