The G-Shock GSTB100-1A combines strength, innovation, and style with a silver stainless-steel and resin case, black dial with silver accents, and black resin strap. A rotating disc dial at 9 o’clock, driven by a dual-coil motor, functions as a stopwatch indicator, alarm display, and battery level gauge, highlighting its functional beauty. Built with a layer guard structure and high-density mounting, it offers a slimmer, more comfortable fit while maintaining G-Shock’s signature toughness. Featuring Bluetooth® connectivity, it syncs with your smartphone for auto time adjustment and world time in 300 cities. Powered by Tough Solar, it delivers long-lasting performance with energy-saving capability, shock resistance, and 200m water resistance. Additional features include dual time display, stopwatch, alarm, Super Illuminator LED light, and a full auto-calendar (to 2099). The rechargeable battery lasts up to 5 months on normal use or 24 months in power-save mode, making it a durable and smart timepiece built for everyday endurance. - Case Size: 58.1 × 53.8 × 14.1mm - Weight: 101g - Materials: Resin and stainless-steel case/bezel, resin band, mineral glass - Water Resistance: 200m - Shock Resistant - Power: Tough Solar (solar powered) with power-saving mode and battery level indicator - Battery Life: Approx. 5 months (normal use) / 24 months (power save mode) - Bluetooth® Connectivity: Smartphone link with auto time adjustment, phone finder, and access to ~300 world time cities - Functions: Dual time (home city swapping), stopwatch, alarm/hourly signal, full auto-calendar (to 2099) - Light: Super Illuminator LED - Accuracy: ±15 seconds per month (without mobile link) - Other Features: Screw lock crown, energy-saving function, analog display with 3 hands and 3 sub-dials (dual time hour/minute, 24-hour, day)