The sky’s the limit with the gravitymaster grb300, a piece of aviation-inspired professional gear designed to work even in the harshest environments, from the g-shock master of g line. High-contrast black and white dial with subtle red color accents evoking the look of a cockpit instrument panel 54. 0mm black bio-based resin case with carbon fiber core and mineral crystal features include world time, timer, stopwatch, alarm, double led light, neobrite, and calendar powered by tough solar smartphone linking using bluetooth⮠black bio-based resin strap; buckle clasp shock-resistant and water-resistant to 200 meters we are an authorized casio dealer