Electro-luminescent backlightAuto light switch, dual illuminator, selectable illumination duration, afterglow Flash alertFlashes with buzzer that sounds for alarms, hourly time signal, countdown timer time up alarm, countdown timer progress beeper, and stopwatch auto start Low temperature resistant (-20C) World time29 time zones (48 cities), city code display, daylight saving on/off 1/100-second stopwatch (ST1)Measuring capacity: 999:5959.99-InchMeasuring modes: Elapsed time, split time, 1st-2nd place timesOther: Auto start 1/100-second stopwatch (ST2)Measuring capacity: 999:5959.99-InchMeasuring modes: Elapsed time, split time, 1st-2nd place times Countdown timerMeasuring unit: 1 secondCountdown range: 24 hoursCountdown start time setting range: 1 minute to 24 hours (1-minute increments and 1-hour increments)Others: Auto-repeat, progress beeper Multi-function alarms5 independent multi-function alarms (4 one-time alarms and 1 snooze alarm) Hourly time signal Full auto-calendar (to year 2099) 12/24-hour format Button operation tone on/off Regular timekeeping: Hour, minute, second, pm, month, date, day Accuracy:±15 seconds per month Approx. battery life: 3 years on CR2025 Size of case : 52×46.3×16.3mm Total weight : 56g