Since its release in 1983, G-SHOCK Toughness watch has been evolving in pursuit of strength without getting tired of. A popular all-black model based on G-STEEL that combines different materials from metal and resin. Black base with black IP metal bezel, this design is chic and fashionable. The base model uses a low-profile module and a carbon core guard construction GST-B400. Combining toughness and design, the G-STEEL series has all black coloring for a wide variety of uses.

Shock resistant construction.
Tough Solar (solar charging system).
Water resistant to 20 ATM.
Mobile link function (works with Bluetooth® communication with compatible mobile phones)
Needle evacuation function (When the needle overlaps with the LCD display, the needle can be temporarily removed from the top of the LCD display).
World time: 38 cities around the world (38 time zones, with automatic daylight saving set) + UTC (Coordinated Universal Time) display and home city time switching function.
Stopwatch (1/100 second (less than 1 hour) / 1 second (more than 1 hour), 24 hour meter, with lap/split
Timer (set units: 1 second, maximum set: 60 minutes, measured in 1 second increments).
5 time alarms, time signal.
Battery indicator display.
Power saving function (after a certain time passes in a dark place, the display will turn off and save energy)
Fully automatic calendar.
Switch between 12 and 24 hour displays.
● Switch sound between ON/OFF
Date display (month/date display replacement).
Day of the week (English, West, French, Germany, I, and Dew)
Double LED Lights: LED light for dial (super illuminator, afterglow function, afterglow time switch (1.5 seconds/3 seconds), LED backlight for LCD parts (super illuminator, afterglow function, afterglow time switching (1.5 seconds/3 seconds) included).
When using the operating time function when fully charged and without solar power, about 7 months when power saving state: about 18 months.
If it is not connected with a smartphone, it will work with normal quartz accuracy (average monthly difference of ±15 seconds).