Details:* Plug and play， easy operation.* Hi-Fi Stereo audio transmitter， enjoy the music as it is.* Ideal choice for car holders， fully use the car speaker for Bluetooth music play， Hands-free call.* Upgrade your tranditional speakers， get rid of the bother of wire now!* Built-in battery， USB cable for power supply.SpecificationSize: 4.1 * 2.8 * 1.0cmPackage Weight: 1.7 oz/49gThe USB charge cable length: 50cmBluetooth Version 3.0 EDRBluetooth Protocol: HSP/HFP/A2DPFrequency Range: 2.4GHZ-2.4835GHZDistance: 10mCharging Input Voltage: DC 5Continuous work time: 4 hoursCharging Time: 1.5 hoursPackage list1 x Bluetooth Audio Receiver1 x USB charge Cable