Casio F108WH-8A F108wh 30m Water Resistance Digital Watch With White Resin Strap Water Resistant, LED Backlight, Daily Alarm 1/100 second digital stopwatch, Hourly Time Signal Auto Calendar, Accuracy: +/-30 seconds per month Battery CR2016, Approx. battery life: 7 years (If watch is never used) Module 3224, Size of case / total weight: 37.5 x 33.5 x 9.5mm / 27g