The Audemars Piguet Royal Oak Perpetual Calendar Openworked reference 26585CE.OO.1225CE.01 is a highly technical 41mm luxury timepiece crafted from brushed and polished black ceramic. This model features the collection’s signature octagonal bezel with eight white gold screws and an integrated ceramic bracelet with a titanium folding clasp. The case measures 9.9mm in thickness, maintaining a relatively slim profile despite its complexity, and is water resistant to 20 meters. It is powered by the self-winding caliber 5135 movement, which is an extensively skeletonized version of the caliber 5134, providing a 40-hour power reserve.
The watch’s complications are displayed on a transparent sapphire dial with smoked external zones for the counters and pink gold applied hour markers. These complications include a perpetual calendar with indications for the day, date, month, and leap year, as well as a moon phase at the 6 o’clock position and a week indicator on the dial’s periphery. The openworked design allows for a clear view of the movement’s components, such as the wheels and levers, which are hand-finished with polished bevels and grained surfaces.
General reviews of the 26585CE highlight its exceptional craftsmanship and the contrast between the black ceramic material and the pink gold accents within the movement. It is frequently praised for its lightweight feel and wearability on the wrist compared to metal alternatives. While some critics find the skeletonized dial busy or difficult to read, the watch is widely regarded as a pinnacle of modern horology and a highly collectible piece due to its limited production and the difficulty of machining ceramic to such high standards. Critics occasionally note the short power reserve and the brittle nature of ceramic as potential drawbacks for daily wear.