Key Highlights
- New El Primero 3600SK calibre with openworked architecture, visible through a smoked sapphire dial and caseback
- High-frequency operation at 5Hz (36,000 vph), measuring 1/10th of a second directly against a 10-second graduated ceramic bezel
- Silicon escape wheel and lever; column wheel and horizontal clutch finished in blue; 60-hour power reserve
- Four versions: two stainless steel, one 18-carat rose gold, and a rose gold limited edition of 10 pieces set with 52 baguette-cut diamonds
- ZENCLASP™ folding clasp — 41 components, tool-free micro-adjustment, validated across 600,000 opening and closing cycles
- Pricing from 14,900 CHF (stainless steel) to 99,000 CHF (diamond limited edition); available at Zenith boutiques and authorised retailers globally
The El Primero, Opened Up
Zenith‘s El Primero has carried one consistent argument since 1969: that mechanical precision improves with frequency. The calibre’s 5Hz beat rate — 36,000 vibrations per hour — was its founding premise, and the ability to measure one tenth of a second mechanically has been its defining capability ever since. At Watches and Wonders 2026, the Chronomaster Sport Skeleton takes that argument and makes it visible.
The sapphire dial, tinted from opaque black at the periphery to clear at the centre, removes the partition between wearer and movement. What previously required removing the watch from the wrist — flipping it over to observe the caseback — is now part of the front-facing experience. The skeletonization preserves structural integrity and chronometric performance; the openworked rotor, engraved with the Zenith star, keeps winding efficiency intact.
Reading Time in Tenths
The central chronograph hand of the El Primero 3600SK completes one rotation every 10 seconds, not every 60. Against the 10-second graduated ceramic bezel, each increment resolves to precisely one tenth of a second — a direct mechanical consequence of the calibre’s architecture rather than an approximation. The column wheel is visible, finished in blue. So is the horizontal clutch. The blue silicon escape wheel and lever occupy a position of deliberate prominence within the openworked layout, their colour marking their function as plainly as any label could.
Four Versions, One Architecture
The collection spans four references across three material families. The two stainless steel variants — one with a green ceramic bezel paired with grey-toned counters, one with a black ceramic bezel carrying the signature grey, anthracite and blue tri-colour counters — are priced identically at 14,900 CHF (16,700 USD). Both are fitted with a three-link steel bracelet and include an additional rubber strap. The tri-colour counter arrangement is a deliberate reference to the original El Primero of 1969, preserved across every generation of the Chronomaster.
The 18-carat rose gold reference — black ceramic bezel, black rubber strap with a matching rose gold folding clasp — sits at 27,900 CHF (31,500 USD). Its warmth against the smoked sapphire dial produces a different register entirely: less the instrument, more the object. A stop-second mechanism across all references ensures accurate time-setting without interrupting the case’s 10 ATM water resistance.
The Limited Edition
Ten pieces in 18-carat rose gold complete the collection. The bezel carries 52 baguette-cut diamonds totalling approximately 5.00 carats, graded F-G colour and VVS clarity. Hour markers are set with additional baguette-cut diamonds in rose gold. At 99,000 CHF (111,000 USD), this reference occupies a different category from the steel sports watches — closer to the high jewellery chronograph than the competition piece — while sharing precisely the same El Primero 3600SK movement. The high-frequency chronograph architecture operates identically regardless of case material.
ZENCLASP™: Three Years of Clasp Engineering
The stainless steel versions introduce ZENCLASP™, Zenith’s new proprietary folding clasp. The development required three years and 1,800 hours of engineering, and its durability validation covered more than 600,000 opening and closing cycles — the equivalent of over a decade of daily use. Forty-one components, including ten ceramic balls that govern both locking and positional accuracy, constitute the mechanism.
Fit Without Tools
The micro-adjustment system allows the bracelet to be resized in 2.5 mm increments across a 10 mm total range, directly on the wrist and without tools. A secondary cover lifts to access the adjustment; the ZENITH star adorns the primary safety cover. The clasp is fully backward-compatible with existing Chronomaster Sport bracelets not originally equipped with it, and Zenith has confirmed its progressive rollout across additional references.
The Chronomaster Sport Skeleton is available now at Zenith boutiques, through the official Zenith website, and via authorised retailers across the GCC and worldwide.
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Frequently Asked Questions
What makes the Zenith Chronomaster Sport Skeleton able to measure tenths of a second?
The El Primero 3600SK calibre operates at 5Hz (36,000 vibrations per hour), allowing the central chronograph hand to complete one rotation every 10 seconds rather than 60. Against the 10-second graduated ceramic bezel, each increment resolves to precisely one tenth of a second as a direct mechanical consequence of the calibre’s architecture.
How many versions of the Chronomaster Sport Skeleton are available and what are the price ranges?
Four versions are offered: two stainless steel models at 14,900 CHF each, an 18-carat rose gold version at 27,900 CHF, and a limited edition of 10 pieces in rose gold set with 52 baguette-cut diamonds at 99,000 CHF.
What is unique about the skeletonized dial design on this Chronomaster?
The smoked sapphire dial transitions from opaque black at the periphery to clear at the centre, making the openworked El Primero 3600SK movement visible from the front without removing the watch. The design preserves structural integrity and chronometric performance while displaying the blue-finished column wheel, silicon escape wheel, and horizontal clutch.
