April 11 2025

Zenith G.F.J.: A Tribute To Chronometric Excellence

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To mark its 160th anniversary at Watches and Wonders 2025, Zenith unveils the G.F.J., a high-horology tribute to its mid-20th century chronometric legacy. Designed around the revered Caliber 135, this new release is both a mechanical milestone and a design showcase that pays homage to one of the most successful observatory chronometers ever created.

Honoring the Caliber 135

Originally introduced in 1948, the Caliber 135 was developed by watchmaker Ephrem Jobin under the direction of Zenith’s Charles Ziegler. Designed specifically for observatory competitions, the movement featured an enlarged mainspring barrel and a bimetallic Guillaume balance wheel to maximize isochronism and accuracy. It was known for its unique layout, where the minute wheel was offset to allow more space for regulating components.

The enhanced version of this caliber, the Caliber 135-O, was hand-finished and regulated by Zenith’s top chronometer specialists. Between 1950 and 1954, it earned over 230 prizes at the Neuchâtel Observatory, making it the most awarded observatory chronometer movement in watchmaking history.

Caliber 135, Reimagined

The G.F.J. marks the first time Zenith has manufactured the Caliber 135 anew since 1962. While the architecture and 13-ligne (29.6mm) diameter remain faithful to the original, subtle updates improve performance and endurance. The hand-wound movement now delivers a 72-hour power reserve, up from the original’s 40 hours. Operating at 18,000 vibrations per hour (2.5Hz), it incorporates a hacking seconds mechanism and is officially COSC-certified, with in-house regulation targeting precision within +/-2 seconds per day.

The visual finishing is equally striking. Movement bridges are decorated with a unique “brick” guilloché motif, inspired by the historic red-and-white brick façade of Zenith’s Manufacture in Le Locle.

Case and Design Details

The watch is housed in a 39.15mm platinum case, with a thickness of 10.5mm and a lug-to-lug span of 45.75mm. A stepped bezel and sculpted lugs provide vintage-inspired geometry, while modern proportions ensure wearability and presence on the wrist.

The dial is a multi-textured display of craftsmanship. At its center lies a disc of deep blue lapis lazuli, naturally speckled with golden pyrite inclusions. Surrounding it is a wide chapter ring finished in the same guilloché pattern seen on the movement bridges. At six o’clock, an oversized small seconds subdial crafted from mother-of-pearl adds a layer of refinement and contrast.

Applied hour markers and 40 white gold minute beads circle the dial, while slender white gold hands complete the ensemble. Each component is individually crafted and assembled by hand.

Limited Edition & Availability

Production of the Zenith G.F.J. is limited to 160 pieces in honor of the brand’s 160th anniversary. It is priced at USD 49,900 and will be available exclusively through Zenith boutiques and authorized retailers, with pre-orders now open.