In 2025, Grand Seiko released one of its most important watches of all time, the SLGB003. The UFA, also known as the Ultra Fine Accuracy, came equipped with a new caliber, the Spring Drive 9RB2.
On the accuracy point, this was a breakthrough that measured precision not by the day, or even the month, but by the year. In fact, Grand Seiko labeled it the “most accurate wristwatch movement powered by a mainspring today,” with accuracy within +/- 20s per year. Big enough news on its own, but Grand Seiko wasn’t done yet. The caliber was also thinner and had a smaller diameter, creating new possibilities for case sizing. And finally, with the release of the SLGB003, the brand had answered the requests of many Grand Seiko fans with one of their most-requested features: on-the-fly bracelet adjustment.