Zenith G.F.J. G.F.J. Calibre 135 Double Signed with Naoya Hida & Co

The Zenith G.F.J. Calibre 135 Double Signed with Naoya Hida & Co. 40.1865-2.0135/01.C220 was introduced in 2026 as the first watch in Zenith’s Double Signed Program. Limited to 10 pieces, it pairs the modern G.F.J. platform with the design language of Japanese independent watchmaker Naoya Hida & Co. The watch is built around the re-engineered Calibre 135, Zenith’s historically significant chronometer movement, which returned to the collection in 2025 as part of the manufacture’s 160th anniversary. For this version, the reference is executed in platinum and fitted with a 39.15 mm case measuring 10.5 mm thick and 45.75 mm from lug to lug. The case frames a solid silver dial that draws from Naoya Hida’s restrained mid-century design vocabulary, specifically the codes associated with the NH Type 2A. All dial indications, including the Zenith and Naoya Hida & Co. signatures, are hand-engraved by master engraver Keisuke Kano and filled with blue Japanese urushi lacquer. The same treatment is used for the hour markers, giving the dial its graphic structure without relying on applied elements. The layout is deliberately simple, with central hours and minutes and a small seconds display at 6 o’clock. The hands are treated with the same level of material specificity. The hour and minute hands are made from solid gold, CNC-machined, and hand-polished, while the small seconds hand is made from steel and heat-blued. The result is a dial construction defined less by surface decoration than by engraving, lacquer filling, metalwork, and proportion. Its double signature is integrated into the dial itself, rather than treated as a separate printed mark. Inside is the hand-wound Calibre 135, visible through the sapphire case back. This modern version of Zenith’s chronometer movement runs at 18,000 vibrations per hour, or 2.5 Hz, and has a 72-hour power reserve. It uses a large variable-inertia balance with a Breguet overcoil, Charles Fleck’s double arrow-shaped regulator, spring-mounted jewel settings for the balance staff, and a stop-seconds mechanism. The movement is COSC-certified and regulated to within +/-2 seconds per day. Its finishing includes broad Côtes de Genève, hand-chamfering, a dark ruthenium treatment, and yellow gold-colored markings. The watch is delivered with three straps: Himeji Kurozan leather, Wagyu leather crafted in Kyoto, and deep indigo Japanese non-stretch denim from Kaihara. It is fitted with a platinum pin buckle engraved with the G.F.J. initials. The case is water resistant to 5 ATM.