G-Shock Gravitymaster GR-B300-1A Tough Solar Bluetooth Watch

The G-Shock Gravitymaster GR-B300-1A is a mission-ready pilot's watch built on Casio's Carbon Core Guard structure, fusing aviation-inspired styling with the shock-resistance, rigidity, and corrosion-resistance that define the G-Shock line. Finished in black with a matching resin case and band, the case measures 59 x 54.7 x 15.7 mm, weighs just 71 grams, and fits wrists from 145 to 215 mm.

Power comes from Casio's Tough Solar technology, keeping the movement charged from any light source for reliable, maintenance-free operation. Bluetooth smartphone link pairs with the G-Shock app for automatic time correction, world time adjustment across multiple time zones, and a Flight Log function that records time and position data. The watch runs on module 5719 and includes dual time, a stopwatch, countdown timer, daily alarm, and a full-auto LED light with Super Illuminator for cockpit-ready legibility.

Rated for 200-meter water resistance (20 bar) and engineered to G-Shock shock-resistant standards, the GR-B300-1A pairs bold analog hands and indices with a digital sub-display for at-a-glance reading in any conditions. Whether you're logging flight time, working a long shift, or just need a rugged everyday tool watch, the Gravitymaster GR-B300-1A delivers G-Shock toughness with serious pilot-watch credentials.