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Slim new G Steel is the ideal introduction to the G-Shock’s unbreakable watches

The G Steel watch range always wanted to be an everyday Casio G-Shock you could wear with casual clothing or with a suit. It just about succeeded in terms of design, but it struggled with wearability simply because it was big, thick, and pretty heavy. The newly announced GST-B400 G Steel watch is different — due to various tech advancements Casio has made to the G-Shock line over the last few years, it’s the slimmest, lightest, and most wearable G Steel yet.

That makes it an ideal introduction to the brand, and as it also comes with a reliable and helpful Bluetooth connection too, we had to take a closer look.

How wearable?

The GST-B400 G Steel is 12.9mm thick and 80 grams, which may still sound quite a bit, but compared to the 14.1mm thick, 100-gram-plus GST-B100, 14.9mm thick GST-B200, and 15mm thick GST-B300 it makes a considerable difference when on your wrist. To further put this into perspective, the 44mm Apple Watch Series 6 is 10.7mm thick, and the 45mm Samsung Galaxy Watch 3 is 11.1mm thick.

Andy Boxall/Digital Trends

It’s G-Shock’s Carbon Core Guard monocoque construction which helps slim the GST-B400 down, and it’s far more effective here than on the GST-B200 and B300 watches. Carbon fiber is immensely strong, very light, and can be set in a variety of shapes, making it ideal for G-Shock watches, as it maintains strength without sacrificing design or adding more weight. It’s used in conjunction with resin to form the monocoque, which is then attached to a stainless steel bezel and mineral glass over the dial.

My review sample is in stainless steel with a tough resin strap, but there are three other color combinations with stainless steel bracelets. This increases the weight to 160 grams though, so the resin strap version is the one to choose if you want to really notice the weight savings on the GST-B400. The new G-Steel has solar charging, Bluetooth, and is shock resistant and water resistant to 200 meters.

Subtle design?

OK, so your definition of subtle may vary, but the GST-B400 is considerably more understated than some of the older G Steel models, and it’s not just because of the slimmer profile. There’s no crown for a start, the guards around the four buttons have been minimized, and the bezel partially obscures the outermost screws holding the case together. The case is 46mm x 49mm, and vastly different from the 58mm x 53mm GST-B100.

Andy Boxall/Digital Trends

This results in the GST-B400 feeling very natural on your wrist. It’s cleaner, less cluttered, and although it doesn’t disappear, it’s not constantly noticeable either. The lugs don’t extend over my 6.5-inch wrist and the slim profile means it happily slips under most of my shirt cuffs, something the GST-B400 never did. The 80-gram weight is far less intrusive and it’s comfortable to wear all day, with the resin strap never getting sweaty or irritating.

I love the use of angles on the case, almost like it has been influenced by an F-117 Nighthawk stealth fighter aircraft, and it catches the light in a very attractive way. The metal has a brushed finish, and the mineral glass isn’t very reflective and remains crystal clear at all times. The dial itself is easy to read due to clear white text on the dark background, and the light illuminates the two digital complications, which can be difficult to read on their own in daylight.

Andy Boxall/Digital Trends

I’m a fan of G-Shock’s over-engineered, industrial-looking watches, but the more mature, easy-to-live-with style of the GST-B400 G Steel is a pleasant change, and it’s a great looking everyday watch.

Connected features

The G Steel range has had a Bluetooth connection for a while, so what’s new on the GST-B400? Don’t expect it to be a full smartwatch, as like many other Bluetooth-equipped G Shock watches this is best described as a connected watch, meaning the smartphone link complements the watch’s existing features rather than introducing a wealth of smarter ones.

Using the excellent G-Shock Connected app — it has a great design, stores all your previously connected watches, and has a reliable link — you can change the standard and world time, set alarms and timers, and use a feature called Time and Place. This works with the GPS on your phone to create a log of the places you visit with a long press of the Search button on the watch, which records each location on a map in the app.

I’m not sure how often I’d use it, but it works well, just as the other in-app smart features do. The GST-B400 isn’t an Apple Watch rival, or a rival to any touchscreen smartwatch, and instead, the connected feature adds simplicity to common tasks performed on the watch. It’s much quicker to change the world time in the app than using the buttons on the watch, for example.

Andy Boxall/Digital Trends

You don’t need to charge the watch’s battery either, as the solar charging takes care of the Bluetooth connection. With a full charge and no exposure to any light, it’ll last for seven months. There’s a battery indicator on the watch and in the app, so you know if it needs to see some sunlight. Connected features need to work seamlessly to be useful, and G-Shock has mastered this with all its Bluetooth-enabled watches.

Worth buying?

One of the most common complaints I hear from people regarding G-Shock watches is that they’re too big, or that the style is too challenging. While the GST-B400 G Steel is still obviously a G Shock watch, it’s no longer a “large” G Shock, and that’s down to the Carbon Core Guard technology, and the company’s continued efforts to miniaturize components. The design is also far less in-your-face than watches like the Frogman or Mudmaster, and really does suit most outfits. I’d go as far as to call it classy.

Andy Boxall/Digital Trends

If you’re not a G-Shock wearer now, but have always liked the almost absolute unbreakability of the watches yet have been put off by the size, the GST-B400 is worth trying on, as I think it will suit more people than previous G Steel models. The connected features won’t alter the way you use the watch, but do simplify tasks you perform on occasion, but best of all is that when you want to use the Bluetooth connection, it operates without fault. It’s not a reason to buy the G Steel, but it’s a great bonus.

The G-Shock G Steel GST-B400-1A, which is the version seen in the photos here, will be available in May for $320 through G-Shock’s own website and its boutique retail stores.

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Andy Boxall
Senior Mobile Writer
Andy is a Senior Writer at Digital Trends, where he concentrates on mobile technology, a subject he has written about for…
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