2100 series Bio-based resin and stainless steel Bio-based resin band Mineral glass Shock resistant 200-meter water resistance Tough solar-powered Wireless linking using Bluetooth Casio watches apps Auto time adjustment 1/100-second stopwatch Countdown timer 5 daily alarms Hourly time signal Full auto-calendar Button operation tone on / off Power saving and battery level indicator Accuracy: ±15 seconds per month Hand shift feature 12/24-hour format Dimensions: L 1.94" × W 1.75" × H 0.47" Style: gskgbm2100a-8b Color: Yellow Material: Bio-based Resin / Stainless Steel