Blue sapphires rather than diamonds is the decision that separates this Royal Oak Concept from everything around it. The openworked white gold dial and inner bezel are set with brilliant-cut blue sapphires, the folding clasp is set with them as well, and the result is a fully set watch in a colour rather than in white. That is far rarer than it sounds. Gem-setting at this level defaults to diamonds because diamonds are colourless and disappear into the metal around them; a coloured stone does not, and setting an openworked dial with sapphires means the mechanism underneath is seen through blue rather than through clear light. The case is white gold, 38.5 mm across and 11.4 mm thick, and the movement carries a flying tourbillon. It is no longer part of the current collection.
The case measures 38.5 mm across and 11.4 mm thick in white gold, which is remarkably slim for a tourbillon and is what makes the reference wearable rather than merely impressive. White gold is the correct metal and the only one that would have held the design together, because it is cool enough to sit behind blue sapphires without warming them, where rose or yellow gold would have shifted the stones toward green. The dial is openworked white gold set with brilliant-cut blue sapphires, and openworking a dial that is also being set is a compounding problem rather than two separate ones: every aperture cut into the dial removes metal that a stone might otherwise have been seated in, so the setting has to follow the openwork rather than the other way round, and the pattern of stones is determined by what the mechanism underneath has left available. The inner bezel is set to match, which carries the blue out to the edge of the dial and frames the openwork. The hands are openworked white gold, skeletonised so they do not block the view of the movement they cross. The strap is hand-stitched light blue alligator in a large square scale, a coarser scale than the fine hide used on dress watches and better matched to the Royal Oak case, closed with a white gold folding clasp that is itself set with brilliant-cut blue sapphires. A light blue rubber strap with a constellation decoration is supplied alongside it. The two supplied straps are doing more than offering a choice of colour, because alligator and rubber put a set watch in genuinely different situations. Alligator with a set clasp reads as formal and keeps the reference in the register its stones suggest. The rubber strap, textured rather than plain, takes the same watch somewhere far less careful, and the fact that Audemars Piguet supplies one at all on a fully set tourbillon is a statement about how the reference is meant to be used. The clasp travels between them, so the changeover is a strap swap rather than a rebuild.
The movement carries a flying tourbillon and a power reserve display, with hours and minutes. A flying tourbillon is supported from underneath only, with no bridge crossing the top of the rotating carriage, so the assembly appears unsupported and the whole mechanism stays visible from the dial side. That is why it is nearly always paired with an openworked dial as it is here, and why the two decisions are really one decision: the openwork exists to show the tourbillon, and the tourbillon is built flying so there is something worth showing. The power reserve display is the second complication and the practical one, showing how much running time remains before the watch stops. That matters more on a tourbillon than on an ordinary watch, because a tourbillon left to run down has to be restarted and reset rather than simply nudged back into life, and knowing where it stands is the difference between wearing the watch and managing it. On an openworked dial the indicator can be read against the mechanism itself rather than needing a panel of its own, which is why it costs the design nothing. There is no date, no chronograph and no seconds display. That reduction is structural rather than restrained, because every additional display on an openworked dial costs a portion of the mechanism's visibility, and a watch built to be seen through cannot afford to be covered up. What the owner gets is a watch with almost nothing to operate and a great deal to look at, which is the correct trade on a reference of this kind and the wrong one for anyone who wants a watch that does things.
Within the Royal Oak Concept collection this belongs to the gem-set flying tourbillons at 38.5 mm, a group Audemars Piguet produces in very small numbers and treats as distinct from the large technical Concept references. Those larger pieces are 44 mm titanium watches carrying repeaters and chronographs and are read as engineering exercises. This one takes the same collection name in a much smaller case and spends its budget on setting rather than on complication count. Its immediate siblings differ only in stone: one set with brilliant-cut diamonds, one with multicoloured gemstones, and the 26228 references alongside them use baguette-cut stones instead of brilliant. Comparing them shows that the stone is genuinely the product here rather than a finish, since case, movement, dimensions and strap are shared across the group.
This reference suits a collector who wants a tourbillon and wants it in colour, which eliminates most of the market immediately. Sapphire-set watches are far less common than diamond-set ones at every level, and blue against an openworked white gold movement produces something that cannot be mistaken for anything else. The slimness is the practical argument. At 11.4 mm this is a tourbillon that fits under a cuff, which is not true of most of them and is the reason the reference gets worn rather than stored. Now that it has left the catalogue the production is closed, and coloured-stone settings in this collection are made in the smallest quantities of anything Audemars Piguet builds. The buyer is someone who has moved past wanting the complication to be the whole story and wants the watch to be beautiful on its own terms as well.
