Zenith's Legendary Chronometer "G.F.J."

LE LOCLE / GENEVA, April 14, 2026: At Watches and Wonders 2026, Zenith unveils the most exclusive interpretation yet of its "G.F.J.": an extremely rare "G.F.J." limited to just 20 pieces, featuring a tantalum case and baguette-cut diamond indexes.

Named after Zenith founder Georges Favre-Jacot, the "G.F.J." was conceived as a modern centerpiece for Caliber 135, the most awarded chronometer movement in watchmaking history. The "G.F.J." collection goes beyond mere re-editions, serving as a platform to explore all realms of technical innovation, where chronometer precision extends into the world of rare, high-tech luxury materials that are inherently challenging to work with. This time, the rigorous mechanism of Caliber 135 is housed in a case made of tantalum. Tantalum, due to its high density and resistance, requires extremely precise control during handling. Zenith has elevated the inherent strength of this material into a defining characteristic of the timepiece's individuality.

Tantalum is characterized by its high density and numerous constraints. Its natural blue-grey hue possesses a subtle luster, offering a deep metallic texture that is neither reflective nor matte. While excelling in corrosion resistance and biocompatibility, it is also known for being extremely difficult to machine. Due to its hardness and weight, processing requires special tools, wider tolerances, and meticulous finishing.

Tantalum is one of the most challenging metals to work with in modern watchmaking. Its extreme hardness and high density resist machining, making finishing at each stage exceptionally difficult. Its reaction to tools is fundamentally different from gold or platinum, and achieving the same level of precision in finishing requires extended manufacturing time, mastery of special handling techniques, and complete control. The 39 mm diameter case inherits the characteristic stepped bezel and sculptural lugs of the "G.F.J.", while the tantalum material lends it a new personality. The compact, weighty, and exquisitely crafted case imparts a quiet strength to this chronometer. The precision invested in this metal achieves an unparalleled level of perfection.

This approach is carefully explored in the dial as well. The black onyx used for the central disc, with its polished finish, boasts a liquid-like texture on its surface. The large small seconds counter positioned at 6 o'clock uses grey mother-of-pearl, adding a delicate variation in color without disrupting the monochrome composition. Encircling the dial, the brick-pattern guilloché on the outer periphery is inspired by the facade of the Zenith Manufacture. Furthermore, 11 baguette-cut diamond indexes accentuate the dial with architectural precision. The combination of linear diamond indexes and slender white gold hour and minute hands creates a restrained composition, where all elements enhance balance and proportion.

Beating at the heart of the timepiece is the Caliber 135, specially developed in the late 1940s for observatory chronometry competitions. The competition version, 135-O, won 235 chronometry awards and achieved 1st place for five consecutive years at the Neuchâtel Observatory from 1950 to 1954. This record remains unbroken.

Re-engineered for the 21st century, this caliber maintains its 13 lignes (30 mm) diameter and 2.5Hz frequency, while incorporating modern technological innovations. It achieves a power reserve of approximately 72 hours. The large balance wheel features regulating screws, a Breguet overcoil, and a distinctive double-arrow shaped regulator for precise adjustment. A hacking seconds mechanism has also been added for more accurate time setting. The movement's accuracy, adjusted to within ±2 seconds daily rate, is COSC certified.

Through the sapphire crystal case back, one can admire the Côtes de Genève decoration, hand-beveled bridges, and a deep dark ruthenium finish that resonates with the hue of the tantalum case. These elements further accentuate the watch's calculated architectural individuality.

The limited production of 20 "G.F.J." watches will be sold at Zenith boutiques.

G.F.J.

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