Zenith G.F.J. Calibre 135 Double Signed is a collaborations born of genuine passion. The Double Signed Programme originated from the encounter between Zenith’s Chief Product Officer Romain Marietta and Naoya Hida in his Tokyo workshop. Their shared reverence for the golden age of chronometry sparked an immediate connection, and the result is a limited edition of ten platinum pieces that carries both signatures with equal conviction.
For Hida, this was no superficial exercise in co-branding. He first encountered the Calibre 135 in the 1990s, studied it, pursued it, and lived with its legacy for decades before being offered the chance to reinterpret it in this form. That depth of personal history gives the watch a resonance that few collaborations can claim.
The Dial
The solid silver dial is where Naoya Hida’s sensibility expresses itself most directly. Its construction draws from the design spirit of Hida’s own NH Type 1 and Type 2 references, favouring restraint, proportion, and disciplined elegance over decorative excess. All markings, including the double signatures of Zenith and Naoya Hida & Co., are precision-engraved using a traditional pantograph engraving machine, a technique that produces crisp, physically defined impressions rather than printed surfaces. The three Arabic numerals at 12, 6, and 9 o’clock receive additional attention: renowned Japanese engraver Keisuke Kano hand-finishes each one individually before the cavities are filled with blue Japanese urushi lacquer. This traditional lacquerwork technique requires multiple applications and careful drying between layers, and it brings a depth of colour to those numerals that no printed ink could replicate. The result is a dial that rewards close attention, revealing its craft gradually.
The hour and minute hands are CNC-machined from solid gold and hand-polished by a team led by master watchmaker Kosuke Fujita, producing softly rounded profiles that catch the light without aggression. The small seconds hand, positioned at 6 o’clock, is crafted in steel and heat-treated to a deep blue, providing the only assertive colour note on an otherwise composed surface.
Legendary Calibre 135
The movement at the heart of this watch carries one of the most storied résumés in Swiss horology. The Calibre 135 holds the record as the most decorated movement from the golden age of observatory chronometer competitions, with Zenith accumulating 2,333 chronometry prizes over its competitive history. Re-engineered for the G.F.J. collection in 2025 to mark Zenith’s 160th anniversary, the calibre now beats at 18,000 vph (2.5 Hz) and delivers a 72-hour power reserve.
The technical architecture includes a large variable-inertia balance wheel fitted with a Breguet overcoil hairspring, which improves isochronism across different positions, as well as Charles Fleck’s characteristic double arrow-shaped regulator for fine rate adjustment. A stop-second mechanism, achieved through a lever that halts the balance on crown pull, allows precise time-setting to the second. Spring-mounted jewel settings protect the balance staff against shock. COSC certification confirms regulation to ±2 seconds per day, putting this movement in a performance class that many modern calibres with far higher frequencies cannot match.
Through the sapphire case back, the finishing reflects the standard introduced across the Zenith G.F.J. collection: broad Côtes de Genève stripes with delicate hand-chamfered edges, all enhanced with a contemporary dark ruthenium surface treatment accented with yellow gold-coloured markings. The contrast between the dark bridges and the gold lettering is striking, and it positions the movement’s decoration firmly in the present while honouring its historical architecture.
Highest Distinction – Platinum
Zenith houses this edition in a platinum case measuring 39.5mm in diameter and 10.5mm in thickness, with a lug-to-lug distance of 45.75mm. Platinum’s density gives it a presence on the wrist that no steel or gold case can quite replicate, and at this scale the proportions feel considered rather than imposing. Water resistance stands at 5 ATM.
Three straps accompany the watch: Himeji Kurozan leather treated with successive layers of urushi lacquer, Wagyu leather finished by Kyoto craftsmen, and a deep indigo denim cloth produced by Kaihara, a mill from Fukuyama with a long heritage of artisanal weaving. The platinum pin buckle carries the G.F.J. initials, engraved to match the dial’s pantograph work.
Final notes
At €65,900 for ten pieces, the G.F.J. Calibre 135 Double Signed with Naoya Hida & Co. is precisely as exclusive as it needs to be. This is the kind of watch that exists because two parties genuinely wanted to make something meaningful together, and ten collectors in the world will be able to wear that meaning on their wrist.
