Casio #EFD105-1AV Men's Multi Alarm Countdown Timer Chronograph Sports Watch Imported Water Resistant, LED Light, Daily Alarm 1/100 second digital stopwatch, Hourly Time Signal Auto Calendar, Accuracy: +/-30 seconds per month Battery CR2016, Approx. battery life: 10 years Module 2518, Case Size: 44.5mm Diameter, 13mm Thickness