Sport Spring Drive GMT SBGE257

A Spring Drive GMT for the next generation
Equipped with a GMT hand. this watch features Grand Seiko's unique Spring Drive caliber. which combines the motive force of a mainspring with the high precision of a quartz watch. Housed in a water-resistant stainless steel case with ceramic bezel. a 24-hour GMT hand and Lumibrite indices for exceptional precision and legibility complemented by the smooth motion glide of Spring Drive.

Specifications
Exterior
Exterior: Stainless steel with ceramic bezel
Case back: Screw case back
Glass Material: Dual-curved sapphire crystal
Glass Coating: Anti-reflective coating on inner surface
LumiBrite: Lumibrite on hands and index(es)
Case size: Diameter 40.5mm Lug-to-lug 48.7mm Thickness 14.7mm
Band width: 20mm
Clasp type: Three-fold clasp with push button release
Movement
Caliber no.: 9R66
Movement Type: Spring Drive
Power reserve: Approx. 72 hours(3 days)
Accuracy: ±15 seconds per month (±1 second per day)
Functions
Water resistance: 20 bar
Magnetic resistance: 4.800 A/m
Other details / Features:
Screw-down crown
30 jewels
24-hour hand (dual time display function)
Power reserve indicator
Calendar-linked time difference adjustment function