This is a rugged outdoor fitness watch, with IP67 water proof for 50 meters and shock resistance. It is a smart device with bluetooth connection to your smart phone(The phone should be iOS 7.0 or above, Android 4.3 or above). It will monitor your steps and calorie during fitness, generate alert for incoming calls or messages. It can also be used as a stop watch or remote camera. For your convenience, it is equipped with replaceable CR2032 button battery with upto 365 days working time. You do not need to charge the battery.