Spring Drive U.F.A.

The pursuit of high accuracy has been the cornerstone of Grand Seiko’s values since its first watch was created in 1960. In 2004, Grand Seiko introduced the Spring Drive Caliber 9R65, pairing the high torque of an unwinding mainspring with electronic watchmaking precision to deliver a monthly rate of ±15 seconds without the use of a battery. Setting a new standard among movements powered by a mainspring, Spring Drive was hailed as a major innovation in modern watchmaking.

This legacy of watchmaking accuracy reaches new heights with the Spring Drive Caliber 9RB2, which receives the U.F.A. designation, standing for “Ultra Fine Accuracy.” The new movement has an astounding annual rate of ±20 seconds, making it the most accurate wristwatch movement powered by a mainspring today. It 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. The frequency of each quartz oscillator is measured at several different temperatures, with the data programmed into the low-power IC for thermo-compensation. A vacuum seal protects the oscillator and sensor from humidity, static electricity, and light, ensuring stable performance.

Beyond its technological mastery, the watch is an expression of the refinement for which Grand Seiko is renowned. Its intricately textured dial captures the beauty of the frost-covered trees that can be observed in the Kirigamine Highlands, to the east of the Shinshu Watch Studio, where all Grand Seiko Spring Drive watches are made. Its silver-tinged blue hue evokes these ice forests seen through crisp, clear air and is beautifully accented by a tempered blue seconds hand.

Thanks to the movement’s compact dimensions – it is 30mm in diameter and 5mm in height – the watch has a case diameter of just 37mm, making it the smallest Grand Seiko Spring Drive model to date and ideal for smaller wrists. In keeping with Grand Seiko’s longstanding determination to create the most comfortable wearing experience, the bracelet features a newly developed three-step micro-adjustment clasp that operates without a tool, allowing precise adjustments in 2mm increments.