Casio G-Shock GST-B100-1AER

About the Watch

The GST-B100-1AER gives the G-STEEL series a powerful instrument expression with silver-colored metal, black resin, and red accent markings. The all-analog front is built in multiple layers, while the disk at the nine o'clock position takes its shape from the turbines of a jet engine. Large indices, exposed screws, and the distinctive bezel create a clear technical character without obscuring the time.

Materials & Fit

The case measures 58.1 × 53.8 mm and is 14.1 mm thick. It weighs 101 grams. The construction uses resin and stainless steel, with Layer Guard where metal and resin layers meet around the forged steel case. Mineral glass protects the dial, and the crown is screw-locked. The black resin band features a pattern inspired by heavy jet engine blades. The high-density mounting keeps the module more compact and thinner than the powerful format of the front might initially suggest.

Highlights

• The shock-resistant construction and water resistance up to 20 ATM are designed for demanding use.
• Tough Solar provides approximately five months of operation without new light exposure, or 24 months in darkness with power-saving mode.
• Bluetooth and the CASIO WATCHES app handle automatic time adjustment, easy settings, and phone finder.
• The stated precision without mobile connection is ±15 seconds per month.

Good to know

• What does the rotating disk show? It indicates alarm status, stopwatch information, and battery level, among other things.
• How does world time work? A separate sub-dial shows a second time, and about 300 world time cities can be selected in the app.
• What everyday functions are available? The watch has a 24-hour timer, daily alarm, and displays date and day of the week.
• How is readability improved in the dark? White Super Illuminator illuminates the dial and continues for a short time with afterglow.