The New 37mm Grand Seiko Spring Drive UFA Lake Suwa SLGB015

Back in April 2025, as the highlight of Watches and Wonders, Grand Seiko unveiled an important new duo of models for its Evolution 9 collection: the titanium SLGB003 and the platinum SLGB001. A new 37mm case, an unprecedented and appealing new dial texture, finally a micro-adjustment on the clasp and, most importantly, the launch of the new calibre 9RB2, also known as the Spring Drive UFA (Ultra Fine Accuracy). These “smaller sisters” of the White Birch Spring Drive SLGA009 were then followed by a purple steel model, the Ice Forest SLGB005, which unfortunately lacked the comfort clasp. Now, it’s time for a new version, which combines everything you could want, as well as the return of the Lake Suwa pattern. Meet the new Grand Seiko Spring Drive UFA Lake Suwa SLGB015. 

Grand Seiko doesn’t reinvent the wheel with the new SLGB015; instead, it unites multiple beloved features into a single watch, which could well be the most accomplished version of the 37mm UFA platform so far. The base is known and shared mostly with the Purple Ice Forest SLGB005, as this new Lake Suwa version is housed in an Ever-Brilliant Steel case. Dimensions are identical to all previous models, meaning a compact 37mm diameter, reasonable 11.4mm thickness (GS has never been the best at making thin watches, but let’s note the effort here) and a watch that is short on the wrist, with a 44.3mm lug-to-lug. The case combines brushed surfaces with Zaratsu-polished accents in a contemporary way, with a thin bezel, angular surfaces and a comfortable 100m water-resistance. The crown screws down, and the caseback features a sapphire crystal.

This Spring Drive UFA SLGB015 also marks the return of the praised Lake Suwa pattern, applied here for the first time in this sub-collection. Identical to the SLGA019, it is presented here in dark blue, but the rest of the dial – hands, applied markers, logos and date frame – are retained for the titanium SLGB003 and platinum SLGB001, despite the different dial texture. This more classic version with a less pronounced texture will undoubtedly become a cornerstone model in the collection.

Inside the case, no surprises as we have the same highly capable, powerful and ultra-precise calibre 9RB2 that was initially presented within the Titanium SLGB003. Using the hybrid Spring Drive technology, the new Ultra Fine Accuracy calibre 9RB2 pushes the limit to an impressive ±3 seconds per month (or ±20 seconds per year), an accuracy that many purely mechanical watches can’t even reach on a daily basis. The process to achieve such precision is explained here. The movement remains identical to the purple SLGB005, measuring 30mm in diameter and 5mm in thickness. This automatic Spring Drive engine relies on a single barrel, which delivers a comfortable power reserve of 72 hours (with a nicely integrated indicator on the back). The open back reveals the Shinshu Watch Studio’s signature finishings, with frosted plates and bridges providing contrast to the polished bevelled edges.

One major difference with the purple SLGB005 is that now, the Ever-Brilliant Steel 3-link bracelet benefits from the 3-step micro-adjustment clasp introduced on the Titanium SLGB003. It enables precise, tool-free adjustments in 2mm increments for enhanced wearing comfort.

Released as part of the permanent collection and available as of early September 2026, the new Grand Seiko Spring Drive UFA Lake Suwa SLGB015 will be priced at EUR 10,400. For more details, please visit www.grand-seiko.com.