It has quality Bluetooth chip to restore stereo music，suitable for home audio or car audio turn into wireless;In order to maintain strong signal，this Bluetooth receiver not used lithium battery，so need DC5V power supply maintaining power and we provide USB power cable;The audio interface is 3.5mm aux，you can using aux audio Line or rca audio Line to Connect Speakers;Note that there is a pairing button in behind，when you first time connect it or increase new bluetooth devices must to be pressed，the second time or more we do not need press it because of has been remembered;When you press the pairing button，you can hear voice of "du du"