Born from Gérald Genta’s legendary 1972 sketch, drawn in a single overnight session, this octagonal icon turned humble steel into the most coveted metal in watchmaking. Collectors chase the 15400 as the last of the Calibre 3120 Royal Oaks, discontinued in 2019 when the 15500 took its place. Presence like this reads equally well under a dress cuff or across a negotiating table.

Presents itself in mint condition with little to no signs of wear. Grande Tapisserie dial fans out in a hand-worked field of tiny pyramids, sliding from matte shadow to sharp glint as light rakes across the surface. Brushed and polished octagonal bezel pins the dial down with eight hexagonal screws locked in perfect alignment. Integrated bracelet pours straight from the case in alternating satin and mirror links that catch the light like liquid metal running down the wrist.

Functions include hours, minutes, seconds, and date. Screw-down crown loosens with a couple of turns and hand-winds the self-winding Calibre 3120 at its resting position, a movement holding roughly 60 hours of reserve and beating at 21,600 vibrations per hour behind a 22-carat gold rotor spinning through the sapphire caseback. First click out quick-sets the date at 3 o’clock, and a second click hacks the seconds so the hands land on the exact tick.

Comes as a complete set, double-boxed with warranty card, instruction booklet, and hang tag.

Few designs earn the word blueprint, yet this octagon rewrote the rules for nearly every luxury sports watch that followed. Steel, shaped by the right hands, has a way of outshining gold, and wrists that understand the difference tend to reach for a Royal Oak first and everything else second. Slip it on, feel the bracelet settle, and the decision tends to make itself.