The Audemars Piguet Royal Oak Selfwinding Chronograph reference 26240BA.OO.1320BA.01 is a 41mm limited edition timepiece created in collaboration with designer Matthew Williams and his fashion label 1017 ALYX 9SM. Crafted entirely from 18-carat yellow gold, the watch features a 12.4mm thick case with a glareproofed sapphire crystal and caseback. It is defined by its minimalist aesthetic, featuring a yellow gold dial with a vertical satin finish that lacks traditional hour markers, date windows, or chronograph sub-dials, leaving only the luminescent yellow gold hands and the engraved logos of both brands.
The watch is powered by the in-house caliber 4409, an integrated self-winding flyback chronograph movement that operates at 4Hz and provides a 70-hour power reserve. This movement utilizes a column wheel and vertical clutch system for precise operation of the chronograph functions, which include hours, minutes, and small seconds despite the lack of dial calibrations. The case is equipped with a screw-locked crown and provides a water resistance of 50 meters, while the integrated yellow gold bracelet is secured with a folding AP clasp.
General reviews of this 202-piece limited edition often highlight its bold architectural presence and the extreme minimalism of the dial design, which transforms the traditional sports watch into a statement of contemporary fashion. While collectors appreciate the exceptional finishing and the substantial 265-gram mass of the full gold construction, some critics note that the lack of indexes and sub-dial markings significantly impacts the legibility and functional utility of the chronograph. Additionally, while the caliber 4409 is praised for its high-end decoration, some users have reported occasional reliability issues common to the 26240 series, such as alignment or drifting of the chronograph hands.