The speaker uses CSR four.0 Bluetooth for high quality music streaming and you will connect the speaker to your smartphone or tablet devices. The speaker arrives with a built-in rechargeable 3600mAh battery and charges by way of the micro USB port. The speaker also occur with a built-in UNC https://www.bluetoothspeaker.top/bt-multi-function-time-alarm-clock-wireless-charging-light-call-function-bluetooth-speaker/