Shock Resistant, Alarm Chronograph, Mineral Crystal, Illuminator Backlight, shock resistant (G-Shock), Electro-luminescent backlight, 1/100 second stopwatch, Measuring capacity: 23 hours, 59 minutes, Measuring mode: net time, split time, 1st-2nd place times, Countdown alarm, Input range: 1 minute to 24 hours, Measuring unit: 1 second Auto-repeat function, Daily alarm, Hourly time signal, Regular timekeeping, 2/24-hour formats, Accuracy: 15 seconds per month, Battery: Approx. 2 years on CR2016.