The Casio GA-B2100-3AER 0 smartwatch combines a round shaped plastic case and green plastic strap with a traditional buckle. It has a black dial which is protected beneath mineral crystal glass. Power is generated by the quartz movement. This model also has a water resistance of up to 200 metres. Accuracy +/- 15 seconds per month Alarm function Hourly time signal: The watch beeps very hour on the hour Automatic calendar Once set, the automatic calendar always displays the correct date. Battery level indicator An indicator shows the current battery level. Bluetooth® Connectivity Connect to compatible smartphones for a range of features Countdown timer Date and weekday display Display illumination Auto Light: The watch dial will illuminate automatically when you tilt your wrist towards you. Once activated, this feature will automatically deactivate after six hours. LED light selectable illumination duration (1.5 seconds or 3 seconds) Hand shift fu