Casio G-SHOCK Casual Digital Men Watch – Black | GD-100-1BDRCasio G-SHOCK Casual Digital Men Watch – Black | GD-100-1BDR combines a rugged large-case design with classic black styling and red G-SHOCK accents. It features Shock Resistant construction, Multi Time for four cities, World Time, an auto LED backlight, a seven-year battery, and 200-meter water resistance. Casio G-SHOCK Casual Digital Men Watch – Black | GD-100-1BDR is designed for users who want a bold, highly readable digital watch with dependable everyday durability. Its classic black resin case and band are highlighted by red brand-color accents, while the large digital display provides clear access to timekeeping and functional information.A high-brightness LED backlight and light-guide plate help make the display easier to read in dark conditions. The watch also supports Multi Time for four cities and World Time across 31 time zones, making it practical for travel and users who regularly track more than one location. Shock Resistant construction, Mineral Glass, and 200-meter water resistance provide reliable protection for casual wear, sports, travel, and outdoor activities. Powered by a CR2025 battery, the GD-100-1BDR provides approximately seven years of operation. Additional functions include a 1/100-second stopwatch, a 24-hour countdown timer, five daily or one-time alarms, Flash Alert, hourly time signal, button-tone mute, and a full auto calendar through 2099. Large digital G-SHOCK designClassic black finish with red accentsShock Resistant construction200-meter water resistanceApproximately seven-year battery lifeMulti Time for four citiesWorld Time across 31 time zonesHome and World Time city swapping1/100-second stopwatch24-hour countdown timerFive daily or one-time alarmsFlash Alert functionAuto LED backlight with afterglowFull Auto Calendar to 2099Button operation tone on/offSpecificationDetailsBrandCasioSeriesG-SHOCKModelGD-100-1BDRBase ModelGD-100-1BCollectionGD-100 SeriesColorBlack / Red AccentsProduct TypeMens Digital WatchDisplayDigitalMovementQuartzCase & Bezel MaterialResinConstructionShock ResistantBand MaterialResinGlassMineral GlassWater Resistance200 m / 20 BarBatteryCR2025Battery LifeApprox. 7 YearsCase Size55 51.2 17.4 mmWeight72 gCompatible Wrist Size145215 mmMulti TimeFour Different CitiesWorld Time31 Time Zones, 48 Cities and UTCDaylight SavingOn / OffHome/World Time SwapYesStopwatch1/100-SecondStopwatch CapacityUp to 23 Hours, 59 Minutes and 59.99 SecondsStopwatch ModesElapsed Time, Split Time and First/Second Place TimesCountdown TimerUp to 24 HoursTimer Setting Range1 Second to 24 HoursAlarmFive Daily or One-Time AlarmsHourly Time SignalYesFlash AlertYesFlash Alert ActivationAlarms, Hourly Signal and Timer CompletionLightLED Backlight with Auto Light and AfterglowIllumination DurationSelectableLED ColorWhiteButton ToneOn / OffCalendarFull Auto Calendar to 2099Accuracy15 Seconds per MonthTime Format12/24-HourRegular TimekeepingHour, Minute, Second, PM, Month, Date and Day