The openworked architecture immediately sets the reference 15407ST.OO.1220ST.01 apart within the Royal Oak collection. Rather than treating the movement as something hidden beneath the dial, Audemars Piguet makes it the visual centre of the watch, revealing the calibre almost in its entirety and allowing the twin balance wheels, bridges and gear train to become part of the design.
The 41 mm stainless steel case retains the unmistakable geometry of Gérald Genta’s Royal Oak, with its octagonal bezel, exposed screws and characteristic alternation of brushed and polished surfaces. These sharply defined finishes continue through the integrated stainless steel bracelet, creating an uninterrupted transition from case to wrist. Measuring approximately 180 mm in overall length and fitted with an Audemars Piguet double deployant clasp, the bracelet is an essential part of the watch’s architecture rather than simply an attachment.
At the centre of the composition is the openworked calibre 3132, fitted with Audemars Piguet’s distinctive Double Balance Wheel mechanism. Two balance wheels and two hairsprings are mounted coaxially on the same axis, a technically ambitious construction developed to improve stability and precision by compensating for potential variations between the two regulating organs. Visible from the dial side, the mechanism gives the watch both its technical identity and much of its remarkable visual depth.
The absence of a conventional dial allows the eye to move through the different levels of the movement, from the applied hour markers and hands to the exposed wheels, bridges and twin balances beneath. Pink gold-toned elements provide subtle warmth against the predominantly steel and rhodium-toned architecture, while the openworked construction remains surprisingly legible despite its mechanical complexity.
Dating from 2018, the present example combines one of the Royal Oak’s most recognisable case and bracelet designs with one of Audemars Piguet’s most distinctive contemporary regulating systems. It is offered with its warranty card; the dial, case and movement are signed.
