The GST‑B100D‑1A9 is part of Casio’s premium G‑STEEL series—a tough solar‑powered analog chronograph featuring a steel bracelet and subtle blue accents. Its refined yet rugged design makes it ideal for both casual style and everyday use.

Case & Bracelet: Heavy-duty stainless steel with polished silver finish and a solid one‑touch folding clasp for sharp styling and durability.
Dial & Display: Fully analog face with sub‑dials; one at 9 o’clock shaped like jet‑engine blades rotates to indicate alarm status, battery level, and stopwatch progress.
Structure: Layer Guard Structure fuses resin cushioning and stainless steel for shock protection, plus Carbon Core Guard for lighter strength.
Water Resistance: Rated 200 meters—safe for swimming, showering, or light water activity
Power: Tough Solar system uses sunlight or indoor light to recharge—up to ~24 months operation with power-saving function enabled
Bluetooth Connectivity: Syncs with the Casio Watches app for automatic time adjustment, world time (approx. 300 cities), dual‑time swapping, phone finder, and alarm/timer settings.
Additional Functions: Includes full auto-calendar (up to year 2099), LED Super Illuminator light, daily alarm, countdown timer, stopwatch, battery level indicator, and Neobrite luminous coating.

G-STEEL GST-B100D-1A9-a Silver blue