Evolution 9

Specifications

About this reference

In 2025, Grand Seiko unveiled the Spring Drive Caliber 9RB2, a groundbreaking movement that received the then-new U.F.A. designation, standing for “Ultra Fine Accuracy.” Boasting an annual accuracy rate of ±20 seconds, Caliber 9RB2 earned the distinction of being the most accurate wristwatch movement powered by a mainspring.* This model is powered by Caliber 9RB1, featuring an improved construction that makes it ideal for sporting conditions while sharing the same attributes as the Caliber 9RB2. The term ushio , which means “tide” in Japanese, evokes the waters that surround the Japanese archipelago. The green dial draws from the tranquil beauty of shallow coastal waters near the shore. * As of April 2026, based on Grand Seiko’s research. Exterior: Exterior: High-Intensity Titanium; Case back: Screw case back; Glass Material: Sapphire crystal; Glass Coating: Anti-reflective coating on inner surface; LumiBrite: LumiBrite on hands, index(es) and bezel; Case size: Diameter 40.8mm Lug-to-lug 48.5mm Thickness 12.9mm; Band width: 21mm; Clasp type: Locking extension clasp with micro-adjustment; The perimeter of Band: 195mm. Movement: Caliber no.: 9RB1 Instructions; Movement Type: Spring Drive; Power reserve: Approx. 72 hours(3 days); Accuracy: ±20 seconds per year (±3 seconds per month). Functions: Water resistance: 300m / 1000ft diver's; Magnetic resistance: 4,800 A/m; Weight: 122 g; Other details / Features: Unidirectional rotating bezel Screw-down crown Allergy-safe metal 33 jewels Power reserve indicator.