G.F.J. Jasper

G.F.J. – THE ONGOING LEGACY OF THE CALIBRE 135

Following the award-winning revival of the G.F.J., ZENITH unveils a new chapter in this collection dedicated to pure chronometry. Named after the initials of founder Georges Favre-Jacot, the

G.F.J. is not a commemorative gesture, but a statement of intent: a return to the very foundations of precision watchmaking. First introduced with the rebirth of the legendary Calibre 135 and honoured with the “Chronometry Prize” at the Grand Prix d’Horlogerie de Genève in 2025, the G.F.J. established itself as a contemporary expression of ZENITH’s historic mastery of observatory timekeeping. Today, it returns in a new limited edition of 161 pieces in yellow gold, featuring a striking bloodstone dial. More than a new material execution, this edition reinforces the G.F.J. as the contemporary home of the Calibre 135: a movement whose story continues to unfold.

From the late 19th century onward, ZENITH built its reputation in observatory chronometry competitions, earning a record 2 333 prizes, more than any other watch brand. At the heart of this golden era stood the Calibre 135.

Produced between 1949 and 1962, the Calibre 135 was developed specifically for chronometry trials. Its competition version, the 135-O, earned 235 chronometry prizes, including five consecutive first prizes at the Neuchâtel Observatory from 1950 to 1954: A record that remains unmatched.

Rather than reproducing the past, ZENITH re-engineered the Calibre 135 for the 21st century. While preserving its 13-ligne diameter (30mm), 18,000 vph frequency and distinctive architecture, notably its oversized balance wheel and offset centre wheel, the new calibre integrates modern materials and technical solutions to enhance performance and reliability.

The barrel now delivers 72 hours of power reserve. The gear train has been optimized for greater efficiency. The large balance wheel features regulation screws and a Breguet overcoil. The signature double arrow-shaped regulator allows for precise adjustment, while a stop-second mechanism enables exact time setting. Each movement is regulated to +/- 2 seconds per day and is officially certified by the COSC.

Faithful to its original purpose, the Calibre 135 finds in the G.F.J. its most natural expression: Where precision is elevated to a philosophy of design.

In this new edition, the G.F.J. embraces a warmer, more luminous presence.

The 39.5mm case is crafted in yellow gold. Its slender proportions, stepped bezel and curved lugs preserve the refined elegance inspired by 1950s chronometers, while the glow of gold enhances its contemporary presence.

Beneath the sapphire box crystal, the dial reveals a rich interplay of textures and materials. Its architecture remains faithful to the original three-part construction:

• A central disc in bloodstone, whose natural veining and inclusions ensure that no two dials are ever identical.
• An oversized small seconds counter at 6 o’clock in mother-of-pearl.
• A peripheral guilloché sector inspired by the brick façade of the ZENITH Manufacture in Le Locle as a subtle tribute to Georges Favre-Jacot’s vertically integrated vision.

Yellow gold applied markers and finely faceted hands complete the composition, balancing mineral depth with architectural precision.

Visible through the sapphire caseback, the hand-wound Calibre 135 reveals a decoration that differs from the previous anniversary edition. Here, the aesthetic returns to more classical codes: broad Côte de Genève refined hand-chamfering and a contemporary dark ruthenium finish accented by yellow gold-coloured engravings.

The architecture remains defined by its oversized balance and harmonious symmetry: A movement conceived not only as a mechanism, but as a chronometric structure. The G.F.J. stands as a focused expression of ZENITH’s chronometric culture: A watch conceived around the movement that shaped its legacy.

Released in a limited edition of 161 pieces, the G.F.J is available for pre-order exclusively from the brand’s physical and online boutiques, as well as through authorized retailers worldwide.

ZENITH: THE HEART OF WATCHMAKING

Founded in 1865 in Le Locle, Switzerland, ZENITH has been at the forefront of Swiss watchmaking for over 160 years, driven by a pioneering spirit and a relentless pursuit of precision. As the first vertically integrated Swiss watch manufacture, ZENITH has continuously revolutionized horology by developing and manufacturing in-house movements, most notably the El Primero, the world’s first automatic, integrated high-frequency chronograph calibre launched in 1969, renowned for its unparalleled precision and high-frequency performance.

ZENITH’s timepieces celebrate its dedication to innovation and exceptional craftsmanship. The CHRONOMASTER collection embodies the expression of mechanical excellence and watchmaking versatility, the DEFY showcases technical innovation and bold design, while the PILOT collection celebrates ZENITH’s storied aviation legacy with distinctive, adventure-ready timepieces. This unwavering commitment to precision has been recognized with an unparalleled 2,333 chronometry prizes, underscoring ZENITH’s enduring legacy of excellence. The calibre 135, having won most of those prizes, went through a modern re-engineering integrating up-to-date technical solutions and materials. ZENITH decided to give it a new home in its newly introduced G.F.J collection.

Throughout its history, ZENITH timepieces have accompanied pioneers who dared to dream big and achieve the extraordinary: from Louis Blériot’s historic flight across the English Channel to Felix Baumgartner’s record-breaking stratospheric free-fall jump. This daring spirit continues to drive the Maison as it redefines the future of Swiss watchmaking. Celebrating over a century and a half of excellence, innovation, and purpose, ZENITH remains at the forefront of Swiss horology, empowering those who challenge conventions and strive for greatness.

From Le Locle to the world, from 1865 to now, ZENITH is the heart of watchmaking.