The Vacheron Constantin Les Cabinotiers Solaria Ultra Grand Complication is a one-off wristwatch with 41 complications, presented by the brand as the most complicated wristwatch ever made. The 18-carat white gold case measures 45 mm in diameter and 14.99 mm thick. Sapphire crystals cover both sides, with a grey-tinted sapphire on the back. Vacheron Constantin does not give a water resistance rating. The front has a black sunray satin-finished dial with four sub-dials: perpetual calendar at 12 o’clock, world time and second time zone at 3, solar indications at 6 and Moon phases with tides at 9. The manual-winding calibre 3655 measures 36 mm by 10.96 mm and has 1,521 components and 204 jewels. It runs at 3 Hz with a 72-hour power reserve, uses a tourbillon with a silicon balance wheel and carries the Hallmark of Geneva.

The functions include a Westminster minute repeater, a split-seconds chronograph with 60-minute counter, a perpetual calendar with ISO week numbers, a 24-city world time, the equation of time, sunrise and sunset, sidereal time and a sky chart. A new celestial object tracking function is a first in watchmaking. The back shows the sky chart and the chronograph hands. The movement led to 13 patent applications, seven of them for the minute repeater. A single watchmaker in the Les Cabinotiers workshop spent eight years developing it. The watch was unveiled at Watches and Wonders 2025 for the brand’s 270th anniversary. It is worn on a black technical calfskin strap with a white gold folding buckle. The price was not disclosed.

The launch drew wide coverage beyond the watch press, from CNN to Worn & Wound, mostly focused on the complication count and the case size, which is less than half the diameter of the Berkley pocket watch. WatchesBySJX called it one of the most fascinating watches in recent memory and praised the silicon balance and modular astronomical module. It also found the dials cluttered and hard to read, the celestial tracker hard to interpret and the Moon phase less precise than expected. Watchonista described it as packed with functions but noted its relatively slim profile. The Solaria Ultra Grand Complication is a unique piece made for the 2025 anniversary, so as of October 2026 it is not in series production.