The sky?s the limit Introducing the GRAVITYMASTER GR-B300, a piece of aviation-inspired professional gear designed to work even in the harshest environments, from the G-SHOCK MASTER of G line. The GR-B300 features a Carbon Core Guard structure, which delivers the shock-resistance, rigidity, and corrosion-resistance of carbon material used in aircraft fuselages. The carbon fiber-reinforced resin case and the seamless bezel design inspired by next-generation aircraft come together in a bold and powerful form.