CASIO G-Shock G-Steel GBM-2100-1A Watch

What this watch is and who it suits

The CASIO G-Shock G-Steel GBM-2100-1A is a solar-powered sports watch with an analog-digital display and 200m water resistance. Its bio-based resin case and strap combine a 49.8 x 44.4 mm octagonal profile with shock-resistant construction. The black dial shows world time across 38 cities, a 1/100-second stopwatch, five daily alarms and a date window. Bluetooth Mobile Link provides automatic time adjustment and settings control from a smartphone.

Check your setup before ordering

Verify that the 44.4 mm case thickness and 49.8 mm width fit your wrist and any cuff or gear you wear over it. The fixed resin bezel and mineral crystal sit flush to the case, so confirm the buckle clasp length suits your strap preference. Ensure you can charge the Tough Solar movement under regular indoor or outdoor light. The Bluetooth link requires a compatible smartphone running the CASIO Watches app for world time sync and alarm configuration.

Thermals noise and power draw

The Tough Solar cell charges from any light source, removing the need for battery changes during normal use. No fan, pump or active cooling exists, so the watch runs silently. Power draw is limited to the analog-digital module, double LED Super Illuminator and Bluetooth radio during sync. The 200m water-resistance rating means the sealed case handles swimming and surface water sports without pressure-related leakage.