The speaker uses CSR 4.0 Bluetooth for high quality music streaming and you will connect the speaker to your smartphone or tablet devices. The speaker comes with a built-in rechargeable 3600mAh battery and charges through the micro USB port. The speaker also appear with a built-in UNC threated gap https://www.bluetoothspeaker.top/bluetooth-speaker-outdoor-classic-design-waterproof-wireless-speakers-high-quality-audio-hands-free/