Built in Battery: The capacity of the built in battery is 1100mAh, and the rechargeable has a long working hour of 10 hours under reception mode. Wide Application: Allows for broad application in climbing and hiking, outdoor activities, site monitoring and so on, very practical and reliable. Simpler Carrying: Comes with a light weight and a compact size as well, the durable radio transceiver is very convenient to carry for your work. And under reception mode it can be used for about 10 hours.