About this item Casual solar-powered watch with multiple functions including multi-band atomic timekeeping, shock resistance, EL backlight, world time (29 time zones, 48 cities), city code display, five daily alarms, 1/100-second stopwatch, countdown timer, full auto-calendar, battery indicator, and power-saving function Turn on or off the auto light function by holding down the light button and turn wrist at a 40 degree angle towards the user in a dark environment Width is 43.2mm Height is 46.7mm Thickness is 12.7mm Lug Width is 16 mm Approximate battery life: 10 months on full charge (without further exposure to light). Receives time calibration radio signals which keep the displayed time accurate Water resistant to 200 m (660 ft): In general, suitable for professional marine activity and serious surface water sports, but not scuba diving Auto light feature will not work if the battery level falls below Medium (marked as M on the face of the watch).