This extremely portable, lightweight wireless audio transmitter &receiver is an ideal wireless audio solution for a wide range of situations and uses 2.Transmitter mode:wirelessly streams audio from your non-Bluetooth TV, home stereo system, or CD player to your Bluetooth headphones or speakers 3.Receiver mode: wirelessly streams audio from your Bluetooth-enabled phone, tablet, or computer to your wired stereo, speakers, or headphones. 4.There is no built-in battery, and it is powered by DC 5V usb interface: A.Insert usb power, the red light is on in the transmitting mode, the red light flashes when pairing, and the red light is always on after the pairing succeeds. B.Insert usb to power on, the receiving mode is blue light, the blue light flashes when pairing, the blue light is always on after pairing is successful. 5.Broad Compatibility: With the included 3.5mm cable, this Receiver Transmitter adapter can widely be used on your computer, laptop, home stereo system, headphone, smartphone, Mp3 player, CD player, etc. Package Includes: 1x Bluetooth 5.0 Transmitter 1x 3.5mm Aux Cable