The pursuit of high accuracy has been the cornerstone of Grand Seiko’s values since its first watch was created in 1960. In the late 1970s, the development of Spring Drive began with an aim to harmoniously blend the traditional energy of a mainspring with state-of-the-art electronic watchmaking advancements. In 2004, Grand Seiko introduced the Spring Drive Caliber 9R65 with a monthly rate of ±15 seconds.
Today, this legacy of accuracy in watchmaking reaches new heights with the announcement of the Spring Drive Caliber 9RB2, which receives the new U.F.A. designation, standing for “Ultra Fine Accuracy.” The groundbreaking movement boasts a level of precision defined not by accuracy in seconds per day, week, or month, but by its accuracy over one year. The automatic U.F.A. movement has an astounding annual rate of ±20 seconds, making it the most accurate wristwatch movement powered by a mainspring today.*
*As of April 2025, based on Grand Seiko’s research.
The new movement achieves its ±20-seconds-per-year accuracy thanks to new and enhanced manufacturing and processing methods for the three-month-aged quartz oscillator, and a newly designed IC. And, as with the 9RA series of Spring Drive movements, the frequency of each individual quartz oscillator is measured at several different temperatures, with the resulting data necessary for thermo-compensation programmed into the low-power IC. Both the oscillator and sensor are vacuum-sealed to minimize temperature differences and protect against external factors such as humidity, static electricity, and light, ensuring precise temperature adjustments and the stable performance of the quartz oscillator. In addition, for the first time in Spring Drive, the new movement features a regulation switch that can be used during after-sales service to correct any divergences in accuracy that may occur over long periods of use.
The dial with pressed pattern inspired by the beauty of ice forests has a silver-tinged blue hue, evoking the ice forests seen through crisp, clear air, and is beautifully accented by a tempered blue seconds hand. Thanks to the movement’s compact design, the new watches have a case diameter of just 37mm, making them the smallest models powered by the 9R series to date and ideal for smaller wrists.
It features a newly developed three-step micro-adjustment clasp that operates without a tool, allowing precise adjustments in 2mm increments for enhanced comfort.
