The Konstantin Chaykin ThinKing Mystery is a watch that we’ve been wanting to review and photograph for quite some time. Finally, yesterday at the SIAR Summer Edition in Mexico City, our friends from Berger Joyeros made that possible for us. While Piaget, Bulgari, and Richard Mille spent the better part of a decade trading the title of world's thinnest mechanical wristwatch back and forth in a Swiss arms race of micron-shaving and corporate R&D, a Russian independent working out of Moscow quietly walked off with the crown.
Konstantin Chaykin first revealed the 1.65 mm ThinKing as a prototype in 2024, refined it into a final prototype the following year, and has now industrialized it as the ThinKing Mystery in a 12-piece limited edition that, by definition, becomes the thinnest mechanical production watch in the world. At only slightly less than twice the thickness of most credit cards, the case profile almost disappears. For context, the Richard Mille RM UP-01 Ferrari measures 1.75 mm thick, the original Bulgari Octo Finissimo Ultra came in at 1.80 mm in 2022, and the subsequent Octo Finissimo Ultra COSC at 1.70 mm. Chaykin's 1.65 mm undercuts all of them, achieved without conglomerate-scale research budgets.
Things to Know About the Watch
The ThinKing Mystery measures 41 mm in diameter and 1.65 mm thick, weighing just 12.1 grams without the strap. The case is machined from a non-magnetic nickel alloy—originally a Soviet-era specification developed for ultra-precision components—and heat-treated for rigidity, hardness, and corrosion resistance.
The "Mystery" name refers to the dial, while the “ThinKing” is a play on the words: think and king. Two transparent sapphire discs replace the traditional Joker-style printed indicators of the Wristmons line, with hours and minutes appearing to float in space, driven laterally by three rollers per indicator.
There is no crown: winding and time-setting are performed on the back of the watch via two patented external tools that attach to the case back, a 47 mm carbon-and-steel winding box and a 94 mm steel key, each fitted with safety clutches to prevent overwinding.
The strap incorporates patented titanium stiffeners and elastic inserts to reduce flex stress on the wafer-thin case.
The Movement
The in-house calibre K.23-3.1 is integrated directly into the caseback, which doubles as the mainplate, and there is no separate movement structure in the conventional sense. Functional jewels are secured by gold chatons set into the back itself. The architecture runs 54 jewels, a dual balance with a patented toothed coupling, and a patented ultra-thin barrel delivering 38 hours of power reserve—up from 32 hours on the original prototype. The trade-off for this construction is a lack of water resistance, with the movement's lubricants exposed to ambient air through the jeweled caseback. Perhaps not the most wearable wristwatch with the back exposed to sweat and other elements.
On the Wrist & Price
When the Richard Mille RM UP-01 Ferrari broke the thinness record in 2022, we questioned whether the watch industry's pursuit of ultra-thinness had crossed into territory where the result no longer looked or felt like a watch but more like a sheet of metal on the wrist priced at over a million per millimeter, with telling the time turned into a puzzle.
The Chaykin complicates that critique. Yes, it is thinner still. But unlike the Richard Mille, the ThinKing Mystery has a visual identity. The ThinKing Mystery does not feel like a watch in any conventional sense; it feels like an object that should not exist on the wrist. The two transparent sapphire discs—a direct evolution of the Wristmons Joker face—give the watch unmistakable Chaykin DNA, and the time is genuinely legible, much better than on the RM. The 41 mm case wears completely flat under any cuff, and Chaykin has been explicit that this is not the endpoint but the foundation for a future production family of ultra-thin watches.
Sticker Price CHF 400,000—approx USD 510,000. More info on Konstantin Chaykin here.
