Royal Oak Perpetual Calendar Openworked 41 Ceramic

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.

26585CE.OO.1225CE.01 stands on its own in this catalogue — no other reference here shares its base number. It pairs a skeleton dial with a titanium, ceramic case. Introduced in 2019. Beyond the time it carries a perpetual calendar.

Skeletonized movement based on AP 5134, which is an extra-thin movement with suspended barrel. The oscillating weight is guided by a peripheral ring rolling on four ruby runners, which reduces friction and wear to the minimum possible. The moon phase indicator is laser microstructured and laid on an aventurine base. The moon phase astronomical indicator requires a correction every 125 years and 317 days.

3 other watches in the library run the Audemars Piguet AP 5135.

Audemars Piguet

Royal Oak Perpetual Calendar 41 White Gold - Diamond / Skeleton

26625BC.ZZ.1223BC.02 · 41 mm

Audemars Piguet

Royal Oak Perpetual Calendar Openworked 41 150th Anniversary

26585XT.OO.1220XT.01 · 41 mm

Audemars Piguet

Royal Oak Perpetual Calendar Openworked 41 Cactus Jack

26585CM.OO.D301VE.01 · 41 mm