Zenith unveils the first fully skeletonised Chronomaster Sport, placing the high-frequency El Primero 3600 calibre at the centre of the design.
Few watchmakers are as closely tied to precision timing as Zenith. Since its founding in 1865, the Le Locle manufacture has built a reputation around technical innovation, culminating in the 1969 debut of the El Primero — the world’s first automatic integrated high-frequency chronograph movement. Beating at 36,000 vibrations per hour, the calibre became a benchmark for mechanical precision and remains one of the most celebrated chronograph architectures in modern horology.
At Watches and Wonders 2026, Zenith expanded this legacy through two distinct launches that explore the maison’s watchmaking identity from different angles. The new Chronomaster Sport Skeleton pushes the El Primero into more expressive territory for the first time, while the G.F.J. in tantalum revisits one of the most awarded observatory chronometer movements in history through an exceptionally restrained and rare execution.
A NEW TRANSPARENCY
At Watches and Wonders 2026, Zenith balances contemporary chronograph innovation with observatory-grade chronometric heritage across its latest releases.
The Chronomaster collection has long served as the modern home of the El Primero, preserving the movement’s defining high-frequency performance while evolving its visual identity. This year, Zenith unveils the first fully skeletonised Chronomaster Sport, revealing the architecture of the El Primero 3600SK beneath a smoked sapphire dial.
The openworked construction highlights the technical sophistication of the calibre without sacrificing functionality or legibility. Zenith’s signature tri-colour counters remain intact, referencing the original El Primero models of 1969, while the dial’s transparent centre exposes key components including the blue column wheel and horizontal clutch system. Baton indexes and faceted hands filled with Super-LumiNova preserve the clarity expected of a sports chronograph.
The collection arrives in stainless steel with black or green ceramic bezels, alongside a rose gold version and a diamond-set limited edition of just 10 pieces. Zenith also introduces the new patented ZENCLASP™, a folding clasp developed over three years to improve ergonomic comfort and bracelet adjustment. Its tool-free micro-adjustment system and ceramic ball locking mechanism reflect the maison’s broader attention to functional refinement beyond the movement itself.
CHRONOMETRY, REFINED
Crafted in tantalum and limited to 20 pieces, the G.F.J. revisits Zenith’s legendary Calibre 135 through one of modern watchmaking’s most demanding metals.
If the Chronomaster Sport Skeleton represents Zenith’s contemporary face, the G.F.J. in tantalum speaks directly to its chronometric heritage. Named after founder Georges Favre-Jacot, the G.F.J. collection was conceived around the legendary Calibre 135, a movement developed specifically for observatory competitions in the late 1940s. Its competition variant, the 135-O, earned 235 chronometry prizes and secured five consecutive first-place victories at the Neuchâtel Observatory between 1950 and 1954 — a record that remains unmatched.
For 2026, Zenith presents the most exclusive interpretation of the model yet: a limited edition of 20 pieces crafted in tantalum, one of watchmaking’s most difficult metals to machine due to its density and hardness. The material’s subdued blue-grey tone lends the 39.5mm case a quiet, architectural character, complemented by a black onyx dial, grey mother-of-pearl small seconds display and baguette-cut diamond indexes.
Inside, the re-engineered Calibre 135 remains faithful to its original proportions and low-frequency construction while integrating modern refinements, including a stop-second mechanism and COSC-certified accuracy of +/- two seconds per day.
Together, the Chronomaster Sport Skeleton and G.F.J. reveal two complementary dimensions of Zenith’s identity. One driven by visible high-frequency performance, the other by the disciplined pursuit of chronometric excellence. Both underline the maison’s enduring belief that technical mastery is best expressed not through excess, but precision.
