Casio
G-Shock
- Reference
- GA b2100-1A
- Movement
- quartz — Casio Module 5689
- Power reserve
- 5040 h
- Case material
- Carbon-reinforced resin
- Diameter
- 45.4 mm
- Thickness
- 11.9 mm
- Lug to lug
- 48.5 mm
- Crystal
- Mineral
- Complications
- world-timer, chronograph, countdown-timer, alarm, date, day, bluetooth
- Acquired
- 2/16/2026
digital
The GA-B2100 is the “CasiOak” — the octagonal G-Shock that borrows the Royal Oak silhouette and pairs it with a carbon-reinforced resin case. Bluetooth sync keeps it accurate, and the world timer, chronograph, and countdown timer round out the module. It is the modern G-Shock that looks like a real watch and shrugs off anything. 45.4 mm, 11.9 mm thick, 48.5 mm lug-to-lug. Acquired 2026-02-16.