Patek Philippe is widely regarded as the pioneer in the field of perpetual calendar chronograph wristwatches, having been the first manufacturer in the world to introduce this groundbreaking complication with the legendary reference 1518 in the late 1940s. A few years later, the firm followed up with the iconic reference 2499, a model that collectors have since dubbed “the perfect wristwatch.” In 1986, Patek Philippe retired the reference 2499 and introduced its successor, the reference 3970. This new reference retained much of the aesthetic charm of its predecessor but featured a significant technical update: the movement was now based on a Lemania ébauche, replacing the Valjoux-based caliber of earlier models. The reference 3970 also introduced a slightly smaller case diameter of 36mm, offering a more contemporary and wearable size. Produced over a span of 20 years, the reference was divided into three distinct series, each with subtle yet meaningful updates.

- First series: Featured a snap-back case.
- Second series: Introduced a solid caseback and was produced concurrently with the ref. 3971, which featured a snap sapphire caseback.
- Third series: Marked by the addition of an “E” for étanche (waterproof), these models were equipped with both a sapphire screw-down caseback and a solid screw-down caseback.

The present example, a Patek Philippe reference 3970ER-012 from circa 2000, belongs to the final series of this celebrated reference. Offered in attractive overall condition and accompanied by its original Certificate of Origin, this timepiece represents a fantastic opportunity to acquire a historically significant and undervalued masterpiece from one of the most revered watchmakers in the world.