Electro-luminescent backlightAuto light switch, 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 Moon data (moon age of the input data, moon phase graph) Tide graph (tide level for specific date and time) 1/100-second stopwatch (ST1)Measuring capacity: 999:5959.99-InchMeasuring modes: Elapsed time, split time, 1st-2nd place timesOther: 5-second countdown 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 5 multi-function alarms (with 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: 2 years on CR2025 Size of case : 52.4×50×17.7mm Total weight : 68.2g