Based on the best-selling G-Shock design, this innovative watch has been stripped down to capture the rugged essence of the original. Perfect for backcountry expeditions and hunting trips far afield, the unit is powered from the modern combination of solar cell and a special rechargeable, secondary battery. Energized by the sun or artificial light, the battery lasts a full 10 months on full charge without exposure to additional light. Battery-power indicator lets you know when it's time to recharge. You’re guaranteed the most accurate time available thanks to the multiband atomic time calibration that’s updated automatically six times per day, or upon request by the user. Full auto EL backlight with Afterglow for easy viewing in any light condition. Includes daily alarms and snooze alarm, hourly time signal, 1/100-second stopwatch with elapsed time, split time and first/second-place times and countdown timer. Shock-resistant. Water-resistant to 200 meters (660 feet). Case diameter: 50mm.