G-SHOCK Master of G MUDMASTER Carbon Core Guard Watch (Orange) GG-B100X-1A9ER

The Carbon Core Guard structure combines carbon-reinforced bio-resin with cylindrical button guards and rubberised gaskets that create a barrier preventing mud, dirt and dust from entering the watch mechanism. Even when completely covered in mud, all buttons and sensors remain fully functional and can be easily cleaned with water.

Yes, this watch is water resistant to 200 metres (20 bar), making it suitable for swimming, snorkelling and water sports. You should avoid pressing any buttons whilst submerged, and the watch is not designed for scuba diving or high-impact water activities.

The battery (CR2025) typically lasts approximately two years with normal use, including occasional sensor and Bluetooth operation. You can have the battery replaced at any authorised G-SHOCK service centre, and regular replacement also provides an opportunity to check the gasket seals remain watertight.

Bluetooth connects the watch to the Casio Watches smartphone app for automatic time updates, easy function settings, Mission Log recording (combining watch altitude data with phone GPS for route tracking), Location Indicator showing bearing and distance to saved waypoints and phone finder. These features are particularly valuable for outdoor activities and navigation.

The triple sensor provides reliable readings when properly calibrated: the compass points to magnetic north and can be calibrated manually, the altimeter measures height using the pressure sensor and should be calibrated to local altitude data before activities, and the thermometer reads ambient temperature accurately when the watch is removed from your wrist. The step-tracking accelerometer rounds out the full quad-sensor package.

Despite the 55.4mm case size, the Carbon Core Guard construction makes this watch surprisingly lightweight, and the lug design helps it wrap around the wrist comfortably. The bio-resin strap adjusts easily and the watch wears well on wrists of 6.5 inches and above, though it does have a bold presence that suits those who appreciate larger, tactical-style watches.

Yes, this watch arrives in official G-SHOCK packaging with all original documentation and carries a full two-year manufacturer's warranty, valid throughout the UK and Europe. We are an authorised G-SHOCK retailer.

Simply rinse the entire watch under running water whilst gently brushing with a soft toothbrush if needed. The mud-resistant construction means dirt washes away easily without affecting functionality. After saltwater exposure, rinse thoroughly with fresh water and dry with a soft cloth.

The Carbon Core Guard case construction layers carbon-reinforced bio-resin with fine resin components, and the bezel features three layers of fine resin with carbon fibre inserts, creating exceptional strength whilst remaining lightweight. The structure protects the module from shock, provides rigidity for the sensor functions and delivers the durability needed for harsh outdoor environments without the weight penalty of an all-metal construction.

Yes, the bio-resin strap can be replaced with genuine G-SHOCK replacement straps in different colours, available from authorised retailers. The original strap's textured design offers excellent grip even when wet, making it ideal for outdoor work and activities.