Casio Protrek PRW2500B-3 Altimeter Watch Imported Multi-Band Atomic Timekeeping (US, UK, Germany, Japan, China, Tough Solar Power, 200M Water Resistant, Duplex LC Display Tide Graph (tide level for specific date and time), Moon Data (moon age of the specific date and moon phase graph), Digital Compass, Altimeter, Barometer, Thermometer Full Auto EL Backlight with Afterglow, 5 Independent Daily alarms, Hourly time signal, World Time 1/100 second stopwatch, Countdown Timer, Battery level indicato, Power saving function, Full auto-calendar (pre-programmed until the year 2099), 12/24 hour formats Button operation tone on/off, Accuracy: +/- 15 seconds per month (with no signal calibration), Storage Battery: Solar rechargeable battery,Approx. battery life: 5-23 months, Module: 3258, Size of case / total weight : 56.3 x 50.6 x 15.0mm / 81g