- Grand Seiko has revealed the most accurate mainspring-powered movement ever made.
- These watches deliver a ±20 seconds accuracy per year.
- Grand Seiko again draws inspiration from its natural surroundings in its Japanese headquarters.
There’s precision, and then there’s whatever Grand Seiko just pulled off in Geneva. Fresh out of Watches & Wonders 2025, the new Spring Drive U.F.A. SLGB001 and SLGB003 stole the spotlight with one of the world’s most accurate releases.
Grand Seiko’s New Calibre 9RB2
Powered by the brand’s new Calibre 9RB2, these watches deliver a barely believable ±20 seconds per year accuracy. Not per day. Not per month. Per year. It’s the most accurate mainspring-powered movement ever made, which means you could wear it for twelve months straight and be off by about as much as you lose just setting the time manually on your vintage Sub.
As with all things GS, the Calibre 9RB2 embodies the brand’s enduring pursuit of precision, refining everything from its in-house aged quartz oscillator to a new vacuum-sealed temperature compensation system that measures and adjusts itself 540 times a day. There’s even a serviceable regulation switch; a first for Spring Drive that allows fine-tuning decades down the line.
Grand Seiko’s Spring Drive remains a strange and beautiful hybrid: 90% mechanical, regulated by a quartz oscillator, but with all the emotion of a hand-built movement. No batteries. No external power. Just a quietly humming fusion of gears, crystals, and craftsmanship. It’s the kind of flex that doesn’t need to explain itself… something that has become a signature for the Japanese watchmakers.
Grand Seiko SLGB003 & SLGB001
Visually, the new U.F.A. models are classic Grand Seiko Evolution 9, boasting sharp angles, razor polishing, and perfect proportions. Sized at 37mm and only 11.4mm thick, both the titanium SLGB003 and the platinum SLGB001 wear smaller and lighter than you’d come to expect.
Especially once the light catches those “Ice Forest” dials that draw inspiration from the frostbitten trees near Shinshu. Depending on the angle, they shift from silver to pale blue, reflecting the transient environment in which these spectacular timepieces are produced.
The SLGB003 in titanium will set you back around $16,300 AUD and lands in Australian boutiques this June. The platinum SLGB001 is a limited run of 80 pieces and clocks in at $58,200 AUD – also releasing in June. Both figures that feel, if not “bargain”, then at least more logical when you factor in everything that’s beating under the hood.
