"Atomic Timekeeping Receives time calibration radio signals which keep the displayed time accurate Auto receive function (4 times per day) Manual receive function Signal: WWVB, Frequency: 60kHz Tough Solar Power Shock Resistant 200M Water Resistant Auto EL Backlight with Afterglow World Time29 times zones (30 cities), city code display, daylight saving on/off 4 Daily Alarms & 1 Snooze Alarm Time Recorder; Memory capacity: 30 records (each record contains month, day, hour, minutes, seconds) 1/100 second stopwatch Measuring capacity: 23:59'59.99"" Measuring modes: Elapsed time, split time, 1st-2nd place times Hourly Time Signal Auto Calendar (pre-programmed until the year 2039) 12/24 Hour Formats Accuracy: ±15 seconds per month (with no signal calibration) Storage Battery CTL1616 (Rechargeable Solar Battery Cell) Battery Power Indicator Power Saving Function Approx. battery life: 11 months on full charge (without further exposure to light) Module 2688 Case Width: 45mm (Approximately 1 3/4"") Case Thickness: 15mm (Approximately 5/8"")"