The Casio GRAVITYMASTER GR-B300-8A2ER is a robust watch designed for aviation enthusiasts. It features a Carbon Core Guard structure, providing shock resistance and durability. The case measures 59 × 54.7 × 15.7 mm and is made from bio-based carbon and resin materials. The watch is powered by Tough Solar technology and offers Bluetooth connectivity for smartphone linking. Additional features include a dual time display, 1-second stopwatch, countdown timer, daily alarm, LED light with afterglow, and a full auto-calendar up to the year 2099. The GR-B300-8A2ER is water-resistant up to 200 meters and has a mineral glass crystal. Reference number: GR-B300-8A2ER.