Introducing the Grand Seiko Spring Drive U.F.A. – Now With a Micro-Adjustment

Grand Seiko has always been about doing things their way. Quietly obsessive, ruthlessly precise, and deeply Japanese in philosophy, they don't scream for your attention, they earn it. And with the new Spring Drive U.F.A. (Ultra Fine Accuracy), they've done it again.

In typical Grand Seiko fashion, this release isn't about chasing trends. It's about doing what Grand Seiko does best: making arguably the most accurate spring-powered wristwatch in the world. The Spring Drive U.F.A. takes their hybrid mechanical-quartz tech and pushes it to a level that's hard to wrap your head around, ±20 seconds per year. Not per month. Not per week. Per year.

But perhaps even more exciting for collectors is the debut of something we’ve all been waiting for: a proper micro-adjustment clasp. The SLGB003 introduces a brand-new, tool-free system that allows 2mm incremental sizing on the fly. For years, this has been a sticking point among Grand Seiko enthusiasts, and it's a huge win to see the brand finally address it in a meaningful way. It's debuting here, but all signs point to this clasp showing up in more references soon. And frankly, it can't come soon enough.

This new movement, the Caliber 9RB2, debuts in two new references: the SLGB001 in Platinum 950 and the SLGB003 in High-Intensity Titanium. And while the tech is impressive, the aesthetics are pure Grand Seiko: poetic inspiration from Shinshu's frosty winters, ice-blue dials, and a case design that stays rooted in the Grand Seiko Evolution 9 style.

The Basics

Case: 37mm x 11.4mm, High-Intensity Titanium (SLGB003) or Platinum 950 (SLGB001)

Crystal: Box-shaped sapphire crystal with anti-reflective coating on the inner surface

Movement: Grand Seiko Spring Drive Caliber 9RB2, automatic, ±20 seconds/year accuracy, 72-hour power reserve, 34 jewels

Water Resistance: 10 bar (100 meters)

Strap Options: Bracelet in titanium with micro-adjust clasp (SLGB003); crocodile strap with platinum/white gold clasp (SLGB001)

Price: $10,900 (SLGB003); $39,000 (SLGB001)

Availability: June 2025; SLGB001 is a limited edition of 80 pieces and boutique-only

The Juice

Let’s start with the movement, because that’s really the headline here. The Caliber 9RB2 takes the foundational brilliance of Spring Drive — a mainspring driving a glide wheel, regulated by an ultra-precise quartz oscillator — and refines it to a degree we haven’t seen before. Grand Seiko has aged and individually selected the quartz crystals, programmed temperature compensation data into a low-power IC, and vacuum-sealed everything to shield it from static, humidity, and light. It even features a regulation switch for future servicing. Yeah, it’s that deep.

And they didn’t just pack this into a chunky case. The U.F.A. models come in at a wrist-friendly 37mm, the smallest Spring Drive 9R series yet. With the low center of gravity and well-balanced proportions of the Evolution 9 design language, it wears like a dream. Grand Seiko knows how to make a watch feel just right on the wrist, and this is no exception.

Now let’s talk about something that collectors have been asking for: the clasp. The SLGB003 in titanium debuts a newly developed micro-adjustment clasp that allows for precise sizing in 2mm increments without any tools. This is a big deal. For years, enthusiasts have wanted Grand Seiko to catch up with some of the industry’s best in this department, and this new clasp shows they’re listening. It's incredibly welcome, and while it's only featured here for now, it wouldn't be surprising to see this clasp quietly rolled out across more models in the near future. It's one of those subtle upgrades that will make a noticeable difference in daily wear.

Then there’s the dial work. Inspired by the frost-covered trees of Shinshu’s Kirigamine Highlands, these dials are subtle masterpieces. The titanium version (SLGB003) has a silver-toned blue dial with a tempered blue seconds hand. The platinum model (SLGB001) goes slightly deeper in hue, with a silver hand gliding across the icy surface. Both showcase the seamless motion of Spring Drive’s seconds hand, which, let’s be honest, still hasn’t gotten old after all these years.

Finishing is what you’d expect: Zaratsu polishing, distortion-free surfaces, mirror transitions with brushed accents, and the kind of restraint that rewards repeat glances. The platinum version leans into elegance with a crocodile strap, while the titanium model gets the brand’s long-awaited micro-adjustable clasp — and I am happy to see it.

Final Thoughts

There’s something both incredibly nerdy and incredibly soulful about this release. The Spring Drive U.F.A. isn’t going to be the flashiest release of 2025, but it might be the most technically impressive. This is Grand Seiko doing what Grand Seiko does best: pushing watchmaking forward with quiet confidence and ruthless attention to detail.

Sure, $39K for the platinum version is a serious chunk of change, and even $10,900 for the titanium might feel like a lot for a three-hander. But if you understand what this watch represents, and if you're the type of collector who appreciates that ±20 seconds per year is absolutely bonkers, then the Spring Drive U.F.A. might just be your kind of crazy.

This isn’t just a step forward for Grand Seiko. It’s a statement. Learn more about the SLGB001 here and the SLGB003 here.