Seiko Combines Spring Drive Precision and Root Beer Style in Its $6,500 Prospex LX GMT

You may be plenty familiar with the Pepsi- and Coke-style bezels — where the colors of the bezels happen to match those of the namesake soda brands. These colloquial nicknames have become common parlance among enthusiasts, but lest we forget about the lesser-known, but arguably just-as-cool “Root Beer” bezels.

First showing up in the ’70s with Rolex’s GMT-Master reference 1675/3, Root Beer bezels offer a much warmer, vintage-style alternative to the cola-looking variants. And while the style is almost exclusive to the Crown, other brands occasionally get in on the action as well, such as Tudor, Citizen, and Jack Mason. You can now add Seiko to the list with its new Prospex LX GMT, which is making a serious case why it might be the best we’ve seen so far.

The Prospex LX Legacy

Before diving into this particular release, it’s worth understanding where the Prospex LX collection fits within Seiko’s lineup. Debuting in 2019, the LX line represents the pinnacle of Seiko’s sports watch offerings — a modern interpretation of the brand’s legendary 1968 Professional Diver’s watch. That ’68 model earned its stripes among actual divers and explorers, and when Seiko re-created it in 2018, it took home the Sports Watch award at the Grand Prix d’Horlogerie de Genève.

The LX name itself comes from the Latin word for light, and it’s fitting. Developed alongside Ken Okuyama Design (the same studio behind some iconic automotive designs), these watches prioritize maximum light reflection through broad Zaratsu-polished surfaces.

Cosmic Inspiration

This U.S. Special Edition draws its aesthetic from the North America Nebula, a stellar formation roughly 2,000 light-years from Earth. The dial’s vertical gradient shifts from deep black at the top to warm brown at the bottom, based on the nebula’s color variations as it fades into space. The bifurcated coloring extends the glossy two-tone Root Beer sapphire bezel as well.

The insert is fully lumed (a nice touch for nighttime legibility), though it’s friction-fit rather than clickable. The rose gold-tone accents on the bezel markings, crown, and GMT hand complement the root beer colorway perfectly, even if actual rose gold would’ve been the cherry on top at this price point.

Scratch resistant thanks to Seiko’s super-hard coating, the 44.8mm titanium case gets a matching bracelet that features a fully brushed finish and a tool-less microadjustment system.

Spring Drive Excellence

The real story here is what’s ticking inside. Seiko equipped this watch with Seiko’s Calibre 5R66 Spring Drive movement — which is functionally identical to the Calibre 9R66 found in Grand Seiko’s Spring Drive GMT models, just with different finishing. For those unfamiliar, Spring Drive is Grand Seiko’s hybrid technology that combines a mechanical mainspring with quartz regulation, delivering an accuracy of ±15 seconds per month, which is more precise than any purely mechanical movement out there.

You also get a 72-hour power reserve (tracked via an indicator at 8 o’clock), an independently adjustable local hour hand for easy time zone changes, and that signature smooth sweep of the seconds hand.

Spec Sheet

Pricing & Availability

At $6,600, the Prospex LX GMT U.S. Special Edition currently stands as the most expensive standard-production watch in Seiko’s catalog. It’s exclusive to the U.S. market (hence the name), though it’s not a numbered limited edition.

Recap

Seiko Prospex LX GMT Root Beer SNR058

Seiko just dropped a Root Beer GMT that might be the best take on the colorway we’ve seen yet — it’s got Spring Drive accuracy, titanium construction with that gorgeous gradient dial inspired by the North America Nebula, and it’s packing tech based on Grand Seiko’s Spring Drive for $6,600. It’s U.S.-exclusive and sits at the top of the Prospex LX line, making it the priciest standard Seiko you can buy right now.

Learn More: Seiko