Casio G-Shock Master of G Gravitymaster GR-300H-5AER

Designed to tackle the most extreme environments, it combines robustness, functionality, and sophisticated style. The carbon fiber-reinforced resin case offers high shock resistance, while the mud-resistant system, stainless steel case back, and reinforced structure ensure excellent protection from dust and mud.

Conceived for exploration, it integrates a digital compass, altimeter/barometer, thermometer, and step counter. Thanks to the CASIO WATCHES app, you can easily adjust the time and use the Mission Log, which automatically records altitude and route data.

The stainless steel bezel with light yellow gold IP finish, brown IP details, and the dark brown resin strap give it a bold and refined character, inspired by the golden horizon where earth and sky meet.

Dimensions: 59 × 54.7 × 15.7 mm
Weight: 71 g
Case and bezel material: Bio-based carbon, bio-based resin, and stainless steel
Structure: Shock-resistant, Carbon Core Guard structure
Water resistance: 20 bar (200 meters)

Power Supply

Power system: Tough Solar (solar powered)

Time Adjustment and Connectivity

Time adjustment: Bluetooth®, with smartphone connection for automatic time adjustment
Mobile Link: Wireless connection via Bluetooth®
App: CASIO WATCHES
App functions: Automatic watch adjustment, easy watch setup, world time for approximately 300 cities, flight log, phone finder function

Strap

Material: Bio-based resin
Adjustment range: 145 to 215 mm

Glass

Type: Mineral glass

Crown

Type: Screw-lock crown

Surface Treatment

Bezel: Light yellow gold ion-plated

Luminescence

Neobrite: Present

World Time

Second time zone: Display of a second time zone
Function: City switching for your time zone

Stopwatch

Measuring unit: 1 second
Measuring capacity: 23:59'59"
Measurement modes: Elapsed time, split time

Timer

Type: Countdown timer
Measuring unit: 1 second
Maximum interval: 24 hours
Start time setting: 1 minute to 24 hours, with 1-minute increments and 1-hour increments

Alarm and Hourly Time Signal

Audible reminder: Daily audible reminder

Illumination

Type: Super Illuminator LED light
Function: Luminescence
LED color: White

Calendar

Type: Full auto calendar until the year 2099
Display: Date

Power Saving

Function: Hands stop automatically to save power when the watch is left in the dark

Battery Indicator

Function: Battery level indicator

Battery Life

Normal use: Approximately 5 months with rechargeable battery, without further exposure to light after a full charge
Power saving: Approximately 18 months with rechargeable battery if stored in total darkness with the power saving function activated after a full charge

Accuracy

Accuracy: ±15 seconds per month without Mobile Link function

Time Display

Analog: 3 hands for hours, minutes, and seconds; the minute hand moves every 10 seconds
Second time display: 3 dials, with hours and minutes of the second time zone, 24 hours of the second time zone, and day of the month
Date display: Date present