The speaker employs CSR four.0 Bluetooth for high quality music streaming and you will connect the speaker to your smartphone or tablet devices. The speaker will come with a built-in rechargeable 3600mAh battery and charges by using the micro USB port. The speaker also appear with a built-in UNC https://www.bluetoothspeaker.top/smart-wireless-subwoofer-loudspeaker-audio-system-sound-outdoor-rechargeable-speaker/