The Casio G-Shock Master or G GW-9400-3ER is a shock-resistant men's watch that works on light energy. You read the time, 24 hour indication and date on it. You also use the watch as a stopwatch, alarm, altimeter and view the times of sunrise and sunset after entering your geographical position. Thanks to the automatic calibration, the position of the hands is checked and corrected every hour. So you always know exactly what time it is, even if the hands are staggered by magnetism or shock. Thanks to the watch is 20 bar waterproof, so you wear it while swimming.