The Casio G-Shock Black Ocatgon Smartwatch GA-B2100-1A1ER combines a 45mm octagonal shaped plastic case and black plastic strap with a traditional buckle. It has a black plastic dial with luminescent hands, date display which is protected beneath mineral crystal glass. Power is generated by the quartz movement. Other features include an alarm, a back light. This model also has a water resistance of up to 100 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 Core guard structure Four stainless steel pipes form a metal frame that joins the bezel securely with the case back for increased shock resistance Countdown timer Countdown Range: 60 minutes, Measuring