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 arrives with a built-in rechargeable 3600mAh battery and charges via the micro USB port. The speaker also appear with a built-in UNC threated hole https://www.bluetoothspeaker.top/tws-speaker-stereo-sound-bluetooth-speakers-china-factory-high-quality-gifts/