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The Encyclopedia of Horology

Wristwatch · Perpetual calendar chronograph

Patek Philippe Ref. 3970ER Perpetual Calendar Chronograph

Partially verified

This Patek Philippe wristwatch, reference 3970ER, is a second-series perpetual calendar chronograph encased in 18k pink gold. Featuring a 36mm case manufactured by Ateliers Réunis, the watch houses the manual-winding calibre CH 27-70 Q, which is based on a Lemania ébauche. The argenté dial displays a complex array of functions including chronograph counters, a perpetual calendar, and a moon phase indicator, all accented by feuille hands. The typography on the dial is noted as American Typewriter style. Produced in a limited quantity within the series, the watch is accompanied by a full set of original documents.

Patek Philippe 3970ER presented alongside its original sale documents dated March 6, 1991.
Patek Philippe 3970ER presented alongside its original sale documents dated March 6, 1991. — Zamanito. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
zamanito.com
Category
Wristwatch · Perpetual calendar chronograph
Maker / attribution
Patek Philippe
Reference
3970ER
Catalogue / lot identifier
Source URL identifies the listing
Source-reported date
1991
Source-reported place
Switzerland

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Case and Dial

The reference 3970ER features a 36mm case constructed from 18k pink gold. The case production is attributed to Ateliers Réunis, a workshop documented as a specialist in Patek Philippe case manufacturing.

The argenté dial presents a warmer silver tone and utilizes feuille-style hands for time indication. The dial layout includes sub-dials for the perpetual calendar and chronograph functions, alongside a moon phase aperture. The font style used for the numerals is identified as American Typewriter.

Evidence for this section
  • “بدنه ساعت با قطر ۳۶ میلی‌متر توسط کارگاه نامدار Ateliers Réunis ساخته شده”
  • “صفحه ساعت با ته‌رنگ نقره‌ای گرم‌تر (Argenté) ویژگی‌های بارز سری‌های نخستین را داراست”
  • “عقربه‌های برگی‌شکل ظریف (Feuille hands)”
  • “تایپوگرافی موسوم به American Typewriter برای نوشته‌ها”

Movement

The movement powering this watch is the Patek Philippe calibre CH 27-70 Q. This movement is based on a Lemania ébauche and integrates a column-wheel chronograph with a perpetual calendar module.

The movement exhibits traditional finishing techniques, including anglage on the bridge edges and decorative patterns on the plates. The movement architecture serves to provide comprehensive calendar and chronograph data within a standard case diameter.

Evidence for this section
  • “کالیبر مکانیکی CH 27-70 Q مبتنی بر پایه موتور برتر لمانیا (Lemania ébauche) تعبیه شده است”
  • “پرداخت‌های سطحی، لبه‌های پولیش‌شده (Anglage) و چرخ‌دنده‌های دقیق آن استاندارد عالی ساعت‌سازی سنتی را منعکس می‌کنند”

Provenance and Documentation

This watch is offered as a full set, including original manufacturer documentation. The papers indicate an original date of sale of March 6, 1991, from a Patek Philippe establishment.

The source notes that this specific reference and metal combination is rare, with estimated production figures for the pink gold version being approximately 60 pieces out of a total 650 examples produced for the second series.

Evidence for this section
  • “این ساعت همچنین همراه با ست کامل مدارک و متعلقات (Full Set) ارائه شده است”
  • “تخمین زده می‌شود از مجموع ۶۵۰ نسخه تولیدشده از سری دوم در تمام فلزات، تنها حدود ۶۰ نمونه از جنس طلای رزگلد تولید شده باشد”

Open research questions

  • What is the specific case serial number range for the second series of 3970ER?
  • Can the provenance documentation be cross-referenced with Patek Philippe extract archives?

Source evidence

Recorded claims and source quotations for Patek Philippe Ref. 3970ER Perpetual Calendar Chronograph
FieldSource-reported valueSource quotation
MakerPatek Philippe“Patek Philippe”
Reference3970ER“رفرنس 3970ER”
CalibreCH 27-70 Q“کالیبر مکانیکی CH 27-70 Q”
Case MakerAteliers Réunis“کارگاه نامدار Ateliers Réunis”
Material18k Pink Gold“طلای رزگلد (Pink Gold 18k)”
ComplicationsChronograph, perpetual calendar, moon phase“کرنوگراف، تقویم دائمی و نمایشگر فاز ماه”

Visible details

  • Case diameter is 36mm in 18k pink gold
  • Dial features feuille hands and moon phase display
  • Calibre CH 27-70 Q movement visible with anglage
  • Includes leather strap

Research qualifications

  • Total production numbers are estimates provided by the source
  • Service history details are not provided in the source

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

ساعت مچی Patek Philippe رفرنس 3970ER کرنوگراف تقویم دائمی سری دوم طلای رزگلد

Reviewed 2026-11-02 · Record 3cbf064f5e

Terms in this record

Glossary explanations for terms named in this object’s record.

Other perpetual calendar chronograph records