The G-Shock GGB100X-1A9 MUDMASTER combines a carbon-fiber bezel with Carbon Core Guard construction for a shock- and mud-resistant design. Bluetooth connectivity links to the CASIO WATCHES app, while onboard sensors provide direction, elevation, pressure, temperature and step-count information.

• 200-meter water resistance
• Bio-based carbon/resin case and bio-based resin band
• Digital compass, altimeter/barometer, thermometer and step counter
• Double LED lighting, world time and sunrise/sunset display
• Approximate battery life: 2 years on CR2025
• Case dimensions: 55.4 × 51.3 × 19.4 mm; weight: 93 g

Fit and everyday functions

• Fits wrists 145–215 mm; domed mineral glass and Neobrite aid readability.
• Digital compass, barometer, altimeter, thermometer and step counter support outdoor timekeeping. The altimeter measures from −700 to 10,000 m in 1 m increments; the barometer measures 260–1,100 hPa.
• Bluetooth links with the CASIO WATCHES phone app for automatic time adjustment, phone finder, activity logs and location features. Location-related functions work with a connected smartphone.
• Standalone world time covers 38 time zones, 38 cities and UTC. Sunrise/sunset display, five daily alarms, stopwatch and countdown timer are also included.
• Hand-shift function clears the digital display; automatic double white LED illumination offers 1.5- or 3-second lighting with afterglow.
• Full auto-calendar through 2099. Accuracy without a mobile connection: ±15 seconds per month.