Casio Mens' Sports 100M Illuminator Digital Watch Model W-741-1BV Electro-luminescent backlight, Timekeeping Mode: Hour, minutes, seconds, am/pm, date and day of the week Time system: Switchable between 12-hour and 24-hour formats, Calendar system: Auto-Calendar set at 28 days for February Alarm Mode: Daily alarm, hourly time signal Stopwatch Mode: Measuring units: 1/100th of the second, Measuring capacity: 59 minutes, 59:99 seconds, Measuring modes: Elapsed time, split time and two finishes Accuracy at normal temperature: +/- 30 seconds a month,Battery: One lithium battery type CR2016, Battery life: Approximately 5 years