Royal Oak Perpetual Calendar Openworked

In Context

At 41 mm it is sized to the current mainstream: 40 mm is the median across every watch measured in this catalogue. At 9.9 mm thick it is about average for a modern wristwatch. The case back is open, so the movement is visible without taking the watch apart, and the sapphire crystal will resist everything short of deliberate abuse. Rated to 20 m, it is protected against rain and splashes and nothing beyond that.

The movement winds itself from the motion of your wrist. 40 hours of reserve carries it overnight, but not through a weekend in a drawer. At 28,800 vph the seconds hand advances 8 times a second.

26685XT.OO.1320XT.01 stands on its own in this catalogue — no other reference here shares its base number. It pairs a skeleton gloss dial with a sapphire case. Beyond the time it carries a perpetual calendar.

The Calibre 7139 is a selfwinding perpetual calendar movement developed by Audemars Piguet for use in modern perpetual calendar wristwatches. The movement measures 29.6 mm in diameter and 4.1 mm in thickness. It is composed of 423 components and fitted with 41 jewels. The calibre operates at a frequency of 28,800 vibrations per hour (4 Hz) and provides a power reserve of approximately 55 hours. Calibre 7139 displays hours and minutes, alongside a full perpetual calendar with indications for day, date, week, month, leap year, and astronomical moon phase. All calendar indications are mechanically programmed to account for varying month lengths and leap years without requiring manual correction until the year 2100, assuming uninterrupted operation. The movement features automatic winding and is engineered to support an openworked architecture, allowing visual access to the gear train, calendar works, and regulating organ when paired with a sapphire or skeletonised dial.

1 other watch in the library runs the Audemars Piguet AP 7139.

Audemars Piguet

CODE 11.59 Perpetual Calendar Openworked White Gold - Black Ceramic

26443NB.OO.D002CR.01 · 41 mm