This is arguably the first openworked version of the legendary Audemars Piguet Royal Oak “Jumbo” Extra-Thin, and so far, it is my favorite.
The perfection lies in the white gold that “AP” used for the watch's exterior finish, both internal and external finishing, as well as the choice of color. The way the watch combines significant weight with lightness is particularly impressive. I had the opportunity to personally acquaint myself with the exclusive watches, which are limited in production, yet still occupy their place in AP's regular Royal Oak collection.
When I say “regular Royal Oak collection,” I refer to the 140 models that make up the current lineup, excluding special series. And there is hardly anything “regular” about it. The term doesn't fit the 44-millimeter white ceramic “RO” Grande Complication, does it? And it certainly doesn't fit the latest version of the “Jumbo,” the skeletonized model 16204BC. I genuinely believe these Royal Oak “Jumbo” Extra-Thin Openworked watches are the most beautiful iteration of the concept to date. Two years ago, AP celebrated the 50th anniversary of the RO model by releasing several special models, including the 16204ST. It was a steel skeletonized version of the model 16202, the successor to the legendary 15202. Yes, the openworked watches remained true to their origins, but the pale gray mechanism spanning the entire case width and the rose gold hands rotating directly above it did not make much of an impression. The blow came later.
Audemars Piguet Royal Oak “Jumbo” Extra-Thin Openworked: The Power of Gray
In pink (16204OR) or yellow (16204BA) gold, the skeletonized version of the “Jumbo” truly impresses - even knocks out. But the combination of colored precious metal and the skeletonized mechanism presented at the exhibition, to my taste, is excessive. The richness of the colored gold alloy seems to overpower the intricate interweaving of the openworked mechanism. White gold is much more introverted. By using this restrained precious metal and combining it with a mechanism that has undergone some aesthetic changes, AP created the best version of the skeletonized “Jumbo.”

It is in the dark that AP found inspiration. Maybe not, but the dark gray mechanism and black inner bezel give the watch more presence, clarity, and visual stability. The watch looks focused. Yes, the skeletonized mechanism resembles a maze. When it is done in a light color, it also looks somewhat undefined. As a result, everything looks blurred. However, the white gold case and bracelet became the backdrop for a well-detailed skeletonized mechanism with visual boundaries thanks to the black outer ring. The white gold hands match the case, and thanks to the contrasting mechanism below, they are also practical.

Caliber 7121 in its Most Modern Form
The openworked caliber 7124 began its life alongside caliber 7121 - the movement that operates in closed versions of the “Jumbo” watches. The movements were developed together, resulting in the case of the 7124 coming with an automatic 211-part caliber measuring 29.6 × 2.7 mm. The 4 Hz caliber has a 57-hour power reserve, a thin rotor rotating in both directions on ball bearings, and displays only hours and minutes.

It is the use of dark gray that gives this mechanism such a strong modern and possibly even industrial look. But it is the hand finishing that sets this caliber apart. It is so refined, so delicate, so mesmerizing and hypnotic thanks to the finishing of even the smallest details. Inside the mechanism, there are no fewer than 324 (!) hand-polished corners. From a distance of 30 centimeters, the watch looks stunning, but from a distance of three centimeters, it truly boggles the mind.

How Do the Royal Oak “Jumbo” Extra-Thin Openwork Watches Look on the Wrist?
“Jumbo” is the perfect size for RO. Since the 16204BC model in white gold has the same dimensions as the 16202 model - 39 mm in diameter, 8.1 mm in thickness, and 48.6 mm from lug to lug - wearing it on the wrist came with no surprises. The RO Selfwinding 15500ST model, measuring 41 × 10.5 mm, is too large for my taste and my wrist. However, the 15550ST model, measuring 37 × 9.1 mm, is slightly too small and too stocky, so the victory went to the “Jumbo.” The quality of the bezel, case, case back, bracelet, and folding clasp is also excellent. As a result, the watch pleases both the eye and the wrist.

About the Price of This Particular Royal Oak
What is not so pleasant is something that, oddly enough, doesn't bother me. It's the price. The Audemars Piguet Royal Oak “Jumbo” Extra-Thin Openworked in white gold is priced at $124,100 USD. It's such a large figure, such an abstract number, that I almost find it hard to evaluate it correctly. Do you compare it with other gold or platinum skeleton watches? You can, but I don't think the target audience works like that when choosing (their next) watch. I can hardly imagine someone looking for skeletonized precious metal watches on a laptop with several open tabs, comparing brands, models, specifications, and prices.
How exactly does one end up buying such a watch? I'm not sure, but I suspect that calls from AP staff to high-profile clients are quite possible. Some of these clients might even buy the watch impulsively in the AP house. However, despite the fact that model 16204BC is part of the regular collection and technically is not a limited edition, its quantity is incredibly small. In other words, the likelihood of you encountering such a model in your local AP house is very low. If you want to get this model and AP hasn't called you yet, it might be worth picking up the phone and finding out what's possible.

So is it worth the price? In a hypothetical scenario where I have an astronomical budget, I wouldn't mind buying it. And skeletonized watches aren't that important to me. It's the size, shape, and “gray matter” inside the case that make me (openly) work - sorry for that.