The first Openworked & Double Balance wheel movement ever made...

Launched at SIHH in 2016, the 41mm Audemars Piguet Royal Oak ref. 15407ST is a landmark in modern watchmaking. It's no surprise it captured the attention of collectors who recognised the investment potential in such an important watch.

Inspired by CEO François-Henry Bennahmias (who successfully led AP for nearly 30 years), the master engineers at AP's Le Brassus HQ invented & developed the pioneering 3132 calibre; a brand-new patented 38 jewel, 5 position movement made up of 245 components. Suspended beneath an off-set, beautifully chamfered yellow gold bridge, two balance wheels & balance-spring assembly are fixed on a singular axis. The results gained are hugely improved precision and stability. In effect, it increases the mass and inertia far beyond what a single balance is capable of. All the more impressive, considering the movement profile measures just 4.4mm thin.

Like a contemporary artwork, the slate grey openworked dial has been created with meticulous attention to detail – the outer chapter ring in brushed slate grey is crowned by the AP logo at 12, and each hour marker is an elongated luminous-filled rose gold octagon, perfectly matched by the rose gold hands. The rest - a fully skeletonised dial, offering a full view of the movement. Fitted to the integral Royal Oak brushed steel bracelet with concealed clasp, wound by its large 22ct gold "AP" oscillating weight, and waterproof to 50m. In immaculate condition, this UK retailed July 2017 example retains exceptional definition between the brushed and polished sections, showing no signs of wear or polishing.

Widely considered one of the most important models in AP's legacy - this is not something we are likely to be offered again anytime soon. Presented with its original Audemars Piguet box, instruction booklet, and UK stamped AP warranty booklet dated July 2017. Guaranteed for 2 years.