Straight from the Casio Vintage Collection comes a timepiece that never goes out of style. The B640 combines style with features Casio is known for such as an EL back-light and a 1/100th second stopwatch. This timepiece is the perfect complement to any outfit. Basic InformationCase size: 38.9 × 35 × 9.4 mmWeight: 49 gCase and bezel material: Resin BandAdjustable ClaspStainless Steel BandWater resistance: 5 ATMPower supply and battery lifeApprox. battery life: 3 years on CR2016 Watch FeaturesStopwatch1/100-second stopwatchMeasuring capacity: 00'00''00 to 59'59''99 (for the first 60 minutes)1:00'00 to 23:59'59 (after 60 minutes)Measuring unit: 1/100 second (for the first 60 minutes)1 second (after 60 minutes)Measuring modes: Elapsed time, split time, 1st-2nd place timesTimerCountdown timerMeasuring unit: 1 secondCountdown range: 24 hoursCountdown start time setting range: 1 second to 24 hours (1-second increments, 1-minute increments and 1-hour increments)Other: Auto-repeatAlarm/hourly time signalHourly time signalMulti-function alarmFlash alert featureFlashes with buzzer that sounds for alarms, hourly time signalLightLED backlightAfterglowLight colourLED: AmberCalendarFull auto-calendar (to year 2039)AccuracyAccuracy: ±30 seconds per monthOther features12/24-hour formatRegular timekeeping:Hour, minute, second, pm, month, date, day Warranty: 2 Year International Manufacturer's Warranty