G-SHOCK GA-B2100-3AER

The G-SHOCK GA-B2100-3A brings a high-utility, tech-driven evolution to the globally praised octagonal “CasiOak” silhouette. Dressed in a rugged, matte army green colorway inspired by classic military tones, this model introduces two of G-SHOCK’s most sought-after premium features — Tough Solar power and Bluetooth® Smartphone Link — without expanding its iconic, ultra-slim profile. Measuring 48.5 mm lug-to-lug, 45.4 mm wide, and a mere 11.9 mm thick, it stands as one of the slimmest solar-powered ana-digi models in the lineup. Its state-of-the-art Carbon Core Guard structure encloses the module in a carbon fiber-reinforced resin inner case, delivering legendary shock resistance and 200-metre water resistance while remaining exceptionally lightweight at just 52 grams.

The dual-layer dial layout enhances spatial depth, highlighting a high-texture finish across the watch face that contrasts beautifully with a multi-segment LCD window and a physical mode/battery indicator wheel at the 9 o’clock position. Via Bluetooth connectivity to the CASIO WATCHES app, the watch performs automatic time corrections four times a day, syncs over 300 world time cities, programs event reminders, and enables a “Time & Place” map log at the push of a button. Powered continuously by any light source through its efficient Tough Solar face, it operates up to 7 months on a full charge without light exposure. Visibility is handled by a high-intensity double white LED Super Illuminator backlight paired with Neobrite luminescent hands.

Basic Information

Reference: GA-B2100-3A (GA-B2100-3AER)
Collection: G-SHOCK 2100 Series (“Solar CasiOak”)
Case dimensions (L × W × H): 48.5 × 45.4 × 11.9 mm
Weight: 52 g
Case and bezel material: Carbon / Resin
Water resistance: 20 bar (200 metres)
Construction: Shock Resistant, Carbon Core Guard structure

Movement & Features

Module type: Analog-Digital Quartz (Module 5689)
Power supply: Tough Solar (Solar powered)
Run time: Approx. 7 months on rechargeable battery (normal use); 18 months in total darkness (Power Saving mode)
Connectivity: Mobile link (Wireless linking using Bluetooth® via CASIO WATCHES app)
App features: Auto time adjustment, easy watch setting, approx. 300 world time cities, Time & Place log, event reminders, phone finder
Stopwatch: 1/100-second (first 60 mins), 1-second (after 60 mins); 24-hour range; elapsed time, lap/split timing
Timer: Countdown timer, 1-second unit, 60-minute range (1-second and 1-minute increments)
Alarm: 5 daily alarms, hourly time signal, battery level indicator
Calendar: Full auto-calendar (to year 2099)
Accuracy: ±15 seconds per month (with no mobile link function)

Exterior

Glass: Mineral glass
Band: Resin band (Army green)
Compatible band size: 145 to 215 mm
Luminescence: Neobrite on hands
Illumination: Double LED light (Super Illuminator, white) for face and digital display with selectable duration (1.5 or 3 seconds) and afterglow

Display

Layout: Analog 2-hand format (hour/minute hands move every 20 seconds), 1 physical indicator dial, digital LCD window
Other features: Hand shift feature (hands move to clear LCD view), power saving, date/month format display swapping, day display selectable in 6 languages, 12/24-hour format