The Konstantin Chaykin ThinKing Mystery is a hand-wound watch only 1.65 mm thick from crystal to case back. Its 41 mm case is made of a non-magnetic nickel alloy and weighs about 12.1 g without the strap. The case also serves as the movement’s mainplate, with jewel bearings set directly into the case back, so the watch has no rated water resistance. The brushed front plate is engraved with Chaykin’s name. Hours and minutes are shown by hands on twin sapphire discs, so the wrist is visible through them. The calibre K.23-3.1 beats at 18,000 vph (2.5 Hz) and has a 38-hour power reserve. To save height it uses a Swiss lever escapement with a split oscillator, placing the balance and hairspring on one axis and the impulse pin and safety roller on another, and a free-sprung balance with four regulating weights.

The watch follows the ThinKing prototype that Chaykin presented in autumn 2024 as the world’s thinnest mechanical watch at 1.65 mm. A key-wound version of that prototype was sold at Phillips in 2025. For the Mystery, unveiled on 2 April 2026, Chaykin developed a new calibre with a longer power reserve than the earlier K.23-0’s 32 hours. He also replaced the prototype’s stainless steel case with the nickel alloy, reportedly to avoid corrosion, and revised the regulator. Winding and setting are done with a stylus-like key that fits into the case back and includes a torque limiter to prevent overwinding. The black leather strap has titanium reinforcements and elastic inserts. The edition is limited to 12 pieces sold directly by the brand at CHF 400,000 excluding taxes.

Watches by SJX treated reaching production with limited research resources as proof of technical skill. It judged the price reasonable next to the Richard Mille RM UP-01, which it put at about USD 1.9 million. The same review noted that the design scores poorly for absolute efficiency and that the rate tolerance of -15/+20 seconds per day is unimpressive by chronometric standards. It also questioned long-term reliability given the exposed movement and lack of water resistance, and said the corrosion claims are hard to verify because the alloy is undisclosed. As of October 2026 the ThinKing Mystery is a limited edition of 12 pieces.