The Audemars Piguet Royal Oak Selfwinding Perpetual Calendar Ultra-Thin reference 26586IP.OO.1240IP.01 is a high-complication timepiece distinguished by its remarkably slim profile. Measuring 41mm in diameter and only 6.3mm in thickness, the case is constructed from satin-finished titanium with a polished 950 platinum bezel and screw-locked crown. This combination of materials is designed to offer a lightweight feel on the wrist while maintaining the aesthetic prestige associated with platinum. The watch features a blue vertically satin-brushed dial, departing from the collection’s traditional Tapisserie pattern to improve the legibility of its numerous indicators.
At the heart of the timepiece is the caliber 5133, which held the record for the world’s thinnest automatic perpetual calendar movement at its release, with a height of just 2.89mm. This feat of engineering was achieved by reconfiguring the perpetual calendar mechanism from a multi-level stack into a single-plane architecture. The movement operates at a frequency of 19,800 vibrations per hour and provides a power reserve of approximately 40 hours. The complications include a perpetual calendar with day, date, month, and leap year indicators, a moon phase display at 12 o’clock, and a day/night indicator. Despite its complex construction, the watch is water-resistant to 20 meters.
General reviews of the 26586IP highlight its technical achievement and wearer comfort, noting that the titanium and platinum construction makes it significantly more wearable than the initial all-platinum prototype. Critics and enthusiasts often praise the increased legibility of the redesigned sub-dials and the modern aesthetic of the brushed dial. However, some reviews point out practical trade-offs necessitated by the ultra-thin design, such as the relatively low 20-meter water resistance and the 40-hour power reserve. While the polished platinum bezel is noted for its brilliance, some commentators have cautioned that it may be more susceptible to visible scratches compared to brushed surfaces. Overall, it is regarded as a significant milestone in modern horology and a primary example of Audemars Piguet’s technical mastery.