2100 series Carbon and resin Resin band Mineral glass Shock resistant Carbon core guard structure 200-meter water resistance Approx. Battery life: 3 years on sr726w x 2 31 time zones 1/100-second stopwatch Countdown timer 5 daily alarms Hourly time signal Double LED light Full auto-calendar (to year 2099) Button operation tone on/off Accuracy: ±15 seconds per month 12/24-hour format Dimensions: 1.9" x 1.7" x 0.4" Compatible band size up to 8.4"