Casio has released a new addition to the aviation concept GRAVITYMASTER Series, part of the G-SHOCK line of shock-resistant watches. The GR-B100 connects to a smartphone app using Bluetooth® to keep accurate time and enable diverse features.

The GR-B100 is the latest to join the GRAVITYMASTER series designed for pilots, whose jobs require strict attention to timeliness.


Using Bluetooth®, the watch connects to the G-SHOCK Connected smartphone app to keep accurate time, including adjusting for daylight saving time and changes in time zone. One new feature of the GR-B100 is a countdown alarm that can count down to a specified date and time, rather than just a time, with the ability to label the event.

The countdown to each event can be displayed on the watch down to the exact second, for detailed time management. The watch also has a flight log function for recording time and location data, with the ability to view points and routes flown on a map from within the app.


The watch face design was inspired by the cockpit indicators of an aircraft, capturing the worldview of the GRAVITYMASTER series. The hour and minute hands and index marks are designed for optimum readability to ensure the user can get the time and other useful information from the watch at a glance.

The watch face also incorporates a large, high-definition LCD for enhanced readability of text and numerical data, such as the time and event labels entered from within the app.


In terms of operability, watch settings such as the world time and alarms can be easily configured from the app. The watch has six buttons that are assigned to a variety of functions, to offer simplicity and ease of use befitting a watch but with access to diverse features.

Technical details

GR-B100-1A2: Black × Blue Strap, Blue dial highlights
GR-B100-1A3: Black × Gray Strap, Green dial highlights
GR-B100-1A4: Black × Orange Strap, Orange dial highlights

Water Resistance: 20 bar

Communication Standard
Bluetooth® low energy
Signal Range: Up to 2m (may differ depending on surrounding conditions)

World Time
Standard time for 39 cities (39 time zones; daylight saving on/off; daylight saving time (summer time) auto switching); Coordinated Universal Time; home time/world time switching

Measuring unit: 1/1000 second, measuring capacity: 24 hours

Countdown Timer
Measuring unit: 1/10 second; countdown range: 24 hours (1-second increments)

5 multifunction alarms (countdown with date); hourly time signal

Other Functions
Smartphone link functions (world time: over 300 cities, automatic time adjustment, Flight Log, easy watch setting), day and date display, full auto-calendar, LED light (Super Illuminator, afterglow: 1.5/3.0 seconds), low battery alert; hand shift feature (hands move out of the way to provide an unobstructed view of digital display contents.)

Power Source
Tough Solar power system (solar-charging system)

Continuous Operation
About 20 months with the power-saving function ON after full charge

Size of Case
62.5 × 53.8 × 17.3 mm

Total Weight
Approx. 87g