Features: [BT 4.2] BT 4.2 ensures faster transmission speed, stable sound performance and longer effective distance. [Deep Bass] Adopting dual 10W Hifi bass stereo music system, the sound box ensures excellent sound quality. [Multiple Play Mode] Supporting various playing modes, such as BT connection, TF card and audio cable connection. [Built-in Lithium Battery] Built-in rechargeable lithium battery, environmental friendly, energy saving and practical. [Rotary Volume Adjustment] Adjust the volume freely, easy and convenient.