... Function*Built-in 2pcs 3.7V/2200mAh Lithium Battery, convenient and environmental*Connect computer with USB data link, used as ... ion Battery*Play time:8-20hrs(Deending on the volume and temperature)*Net weight:360g(Including battery)*Dimension:118*88* ... Audio cable x 1pc*Hanging belt x 1pc Applications Teaching, Tour guiding, Morning exercise, Training, Sports, Speech,Publication,Outdoor entertainment ...