Audemars Piguet Royal Oak Skeletonized Perpetual Calendar

About this reference

The Audemars Piguet Royal Oak Perpetual Calendar Openworked reference 25829ST was produced from approximately 1997 through 2014. Collectors prioritize this reference for its ultra-thin caliber 2120/2802, which measures 4mm in thickness and features a hand-finished skeletonized movement visible through sapphire crystals on both sides. The 39mm stainless steel case maintains the "Jumbo" proportions favored by purists, distinguishing it from later 41mm iterations. Production numbers were limited, with estimates suggesting fewer than 1,000 units were manufactured in steel over its seventeen-year run. On the secondary market, this reference typically commands prices in the mid-to-high six-figure range, often fluctuating between $250,000 and $450,000 depending on provenance and condition. A notable production detail is the transition from the "straight" Audemars Piguet logo to the curved "Audemars Piguet & Co" script on the rotor, a nuance often used to date specific examples within the production cycle.