Bluetooth Audio Adapter: This Bluetooth transmitter receiver can add Bluetooth functionality to your device, allowing you to enjoy wireless audio on devices that previously did not support Bluetooth(such as TV/PC/gaming device/mp3/mp4, vintage stereo, home stereo, speakers, car stereo). You will be able to enjoy the convenience of the Bluetooth feature but not have to replace them. 2-In-1 Bluetooth Transmitter Receiver: In transmitter mode(Tx), the Bluetooth adapter is plugged into an audio source such as a TV/PC/MP3/MP4 player and transmits audio to Bluetooth headphones/speakers. In receiver mode(Rx), Bluetooth audio adapter can receive audio from a phone/tablet and play music on a wired speaker/stereo. RCA & AUX to Bluetooth, TF Card Play: This Bluetooth audio transmitter receiver not only supports RCA(L/R) & 3.5mm(AUX) audio output, but also allows you to insert a TF card into the Bluetooth audio receiver(in receive mode), and then just turn on the speakers and let the music flow. Plug and play, easier to use.