Audemars Piguet Quantieme Perpetual Openworked 25668BA, 1980s

Dealer description — S.Song Watches

Famed for its legendary avant-garde designs and uncanny ability to chart its own course, Audemars Piguet has long been established as one of watchmaking's most influential manufactures. With a long list of industry firsts to its name, innovation has always been central to the brand's identity. When Audemars Piguet introduced the Perpetual Calendar Openworked Ref. 25668BA in 1988, it further reinforced that reputation. Produced until 1993, the Ref. 25668 was made in just 205 examples, of which only 94 were cased in 18-carat yellow gold, like the example offered here. This reference combines two disciplines that Audemars Piguet has long championed: the perpetual calendar and the art of open-working. Given the immense technical precision, craftsmanship and hand-finishing required to produce each watch, it is no surprise that the Ref. 25668BA remains as rare and desirable as it is today. At the heart of the watch lies its beautifully open-worked dial, which showcases the perpetual calendar mechanism in full view. Blued steel hands indicate the calendar functions, while a striking moon phase display occupies the 6 o'clock position. The hours and minutes are displayed via matching yellow gold hands, creating a pleasing contrast against the intricately skeletonised movement beneath. Despite the complexity of its construction, the watch remains remarkably legible. Powering the Ref. 25668BA is the automatic Cal. 2120, one of Audemars Piguet's most historically significant movements. Renowned for its exceptionally thin profile, the Cal. 2120 remained in production until 2022 and formed the foundation of many of the brand's most important references. As an early example from the late 1980s, this watch predates the introduction of the leap-year indicator. While this may make the perpetual calendar slightly less convenient in practical terms, collectors often favour these earlier references for their historical significance and rarity. The movement's open-worked architecture reveals an intricate network of gears, bridges, springs and plates, all meticulously hand-finished to the standards expected of a member of watchmaking's Holy Trinity. Viewed through the sapphire crystal caseback, the watch reveals another highlight: an elaborately engraved 18-carat yellow gold rotor suspended above equally ornate open-worked bridges, demonstrating the extraordinary level of attention devoted to even the smallest visible surfaces. Housed within a 36mm 18-carat yellow gold case, the Ref. 25668BA remains remarkably wearable. Its slim profile, elegant proportions and short downturned lugs allow it to sit comfortably on the wrist, while the stepped bezel adds visual depth and refinement. Combined with the endlessly fascinating open-worked movement, the result is a watch that rewards prolonged observation, continually revealing new details with every glance.