Why I’m still smitten with the Zenith G.F.J. Calibre 135
Jamie WeissWhen I first got my hands on the Zenith G.F.J. Calibre 135 at Watches and Wonders in Geneva earlier this year, I was nothing short of blown away. In fact, in our ‘Kiss, Marry, Kill’ wrap-up at the end of the fair, it was my ‘marry’, and you can see in that video we shot that I was literally at a loss for words – just gushing over this Zenith. I said then that I had one of the most visceral reactions I’ve ever had to a watch when I first encountered the G.F.J., such was my immediate love of the thing. But it’s easy to get caught up in the mania of a big watch fair. With a bit of distance, how do I feel about it now?
Well, over half a year later, and with significantly more time spent with the G.F.J., I’m still in love with it. It’s a strong contender for the best watch of the year, and that’s saying something, even in the context of Zenith’s massive 2025, where the Le Locle brand has celebrated its 160th anniversary with a boatload of special releases (with our Zenith x Time+Tide Defy Skyline Skeleton White Surfer Ceramic forming part of those celebrations, too…)
Let’s start with a short history lesson
G.F.J. stands for Georges Favre-Jacot, the enterprising watchmaker who founded Zenith back in 1865. Favre-Jacot’s motivation for founding the manufacture was nothing less than wanting to create “the perfect watch”, and he approached this in a methodical, innovative way: Zenith was one of the watch industry’s first fully vertically integrated manufactures, bringing all the disparate elements of watchmaking under one roof. Indeed, that’s reflected in the construction of the Zenith G.F.J., and is what makes it so exciting: it showcases multiple different elements of Zenith’s savoir-faire in one cohesive package, as well as expressing a dimension of watchmaking we haven’t seen from Zenith in a while.
But back to the history lesson: fast forward a few years from Zenith’s founding, and the watchmaker was already submitting its movements to timing competitions in its pursuit of chronometric perfection. Zenith took part in these trials as early as 1897, and in fact, over the years, Zenith movements have won a record 2,333 chronometry prizes, more than any other brand in the industry. One of these movements would prove to be particularly influential, and it’s not the El Primero, as you might be guessing: it’s the Calibre 135, which was specifically developed to compete in chronometry competitions at Observatories like Neuchâtel, Geneva or Besançon.
Originally produced from 1949 to 1962, the calibre 135 alone won 235 chronometry prizes, a record in the history of watchmaking. It saw a brief and special revival in 2022, when Zenith collaborated with Finnish master watchmaker Kari Voutilainen and auction house Phillips on a limited run of 11 watches utilising new old stock calibre 135 observatory trial movements. These watches all retailed for well over CHF 100,000, though, making them inaccessible to the vast majority of watch collectors. That brings us to 2025 and the Zenith G.F.J., which has fully resurrected the calibre 135, while also bringing it into the 21st century.
The 135’s return
While this new calibre 135 retains the same dimensions and overall design of the historic movement, it’s no simple reproduction. Firstly, it now boasts a 72-hour manually-wound power reserve, a big boost over the original’s 40 hours. It also now has hacking seconds, in order to better facilitate accurate time-setting, and a balance staff protected by spring-mounted jewel settings.
It still retains the 50s-era movement’s signature double arrow-shaped regulator, Breguet overcoil, 2.5 Hertz beat rate, and most notably, its massive 13mm balance wheel: a reflection of its mid-century origins, where having such a large balance wheel was important for regulating a movement to prize-winning accuracy. Speaking of accuracy, this modern calibre 135 is regulated to ±2 seconds per day, certified by COSC.
The biggest noticeable difference this revived 135 brings to the fore is how it’s finished. Rather than côtes de Genève, its bridges feature a brick-shaped guilloché pattern, inspired by the Zenith manufacture’s distinctive façade of red and white-painted bricks. It might be a reference to a 160-year-old building, but the effect is quite modern, as well as masterful. I’m not sure if it’s hand-guillochéd or done by machine – I’ve heard both claims – but regardless, it’s very impressive.
A delightful dial
That story continues when you flip the watch over, which takes me to the next element of Zenith that the G.F.J. celebrates – its metiers d’art. And it’s really the dial of the G.F.J. that had me so immediately smitten. It’s constructed from three different materials: firstly, we have an outer ring with the same brick-shaped guilloché seen on the movement, cast in blue. This is topped by thin, 18-carat white gold applied indices, which, alongside the guilloche, provide amazing light play.
Then, we’ve got a main dial section made from one big piece of lapis lazuli. This watch might be a tribute to the design codes and technology of the 50s, but stone dials are absolutely on trend right now, making it a prescient choice. Zenith has selected lapis with very few inclusions, providing a rich, blue expanse with subtle variations, ensuring each G.F.J. is unique.
Lastly, we have a section of blue-dyed mother-of-pearl forming the small seconds indicator at 6 o’clock. I’ve personally not seen mother-of-pearl dyed with such a rich hue, and including it in a masculine dress watch like this, paired with another natural stone? That’s kind of out there, although the resulting dial is totally cohesive. Of course, blue is Zenith’s signature colour, with most of this year’s 160th anniversary pieces celebrating this rich tone, which Zenith says is emblematic of the brand’s connection to the sky and lofty goals for precision.
The dial is absolutely meticulously constructed, too. As I said back in April, after getting a loupe on the watch, the fine details between the guilloche, indexes, pad printing, and hands are just spectacular. It’s Holy Trinity-level good – and indeed, there’s a real Calatrava vibe about the G.F.J… Like a Calatrava that’s let its proverbial hair down a little.
The case is pretty nice, too
All this gorgeous blue is encased in a luxurious 39mm wide, 10.5mm thick platinum case, which has a stepped bezel and curved, stepped lugs, with alternating brushed and polished surfaces – and those polished surfaces really pop, as you can see from Marcus’ superb photos and in our video review.
Being platinum, it has a reassuring heft on the wrist, which can be dialled up to 11 if you choose to option your G.F.J. with a platinum bracelet, a seven-link design that repeats that brick motif down its central links. While Zenith hasn’t publicised the cost of the platinum bracelet, I have it on good authority that it more than doubles the final price of the watch… It certainly doubles the weight.
However, as standard, the watch comes mounted on a dark blue alligator leather strap, which also has a hand-guilloched platinum pin buckle with the same brick motif, which is an elegant touch. Actually, it comes with three straps: an alligator strap, as well as two calfskin straps, one in smooth black leather and one in dark blue “Saffiano” leather. All three straps have quick-release spring bars, facilitating easier exchange: Zenith certainly gets credit for shipping the watch with three straps, too.
Closing thoughts
Look, it should be pretty clear by now that I like this watch. I just think it’s such a neat, cohesive expression of Zenith’s history and future. It’s a timeless, formal design, but it’s also quietly bold, with a unique mix of dial materials. Its revived calibre 135 speaks to the brand’s history, but iterates rather than replicates… Zenith in today’s market is mostly known for high-beat chronograph movements and making larger, sporty, contemporary watches. So to see a more demure, manual-winding dress watch with a natural stone dial is a refreshing change of pace.
The really exciting part is that Zenith is describing the G.F.J. as a totally new collection, which gives me hope that we’ll see more variations on its design in the future. While I’m a big fan of this inaugural model’s blue look (I’m a sucker for platinum, too) and I’m already thinking of ways I can justify purchasing one, it would be very cool to see a version of this with an onyx dial, black mother-of-pearl and cased in steel. A man can dream, I suppose.
Zenith G.F.J. Calibre 135 pricing and availability
The Zenith G.F.J. Calibre 135 is a limited edition of 160 pieces and is available now from Zenith boutiques and via the brand’s e-commerce platform. Price: from £44,900/US$49,900/A$78,400
| Brand | Zenith |
| Model | G.F.J. Calibre 135 |
| Reference Number | 40.1865.0135/51.C200 |
| Case Dimensions | 39.15mm (D) x 10.5mm (T) x 45.75mm (LTL) |
| Case Material | 950 platinum |
| Water Resistance | 50 metres |
| Crystal(s) | Sapphire front and back |
| Dial | Lapis lazuli, blue dyed mother-of-pearl and brick guilloché |
| Strap | Comes with three straps: dark blue alligator leather strap with platinum pin buckle, black smooth calfskin leather and blue “Saffiano” calfskin leather Optional seven-link platinum bracelet available for purchase |
| Movement | Calibre 135, in-house, manual-winding, COSC-certified |
| Power Reserve | 72 hours |
| Functions | Hours, minutes, small seconds |
| Availability | Limited edition of 160 pieces |
| Price | From £44,900/US$49,900/A$78,400 |