Bluetooth 5.4 Transmitter & Receiver, Four-in-One Bluetooth Receiver Bluetooth Transmitter 3.5mm Aux Bluetooth Adapter Audio Receiver for Car (Receiver + Transmitter) Hands-free Calling, Applicable to Car Speakers/TV/Headsets/Speakers/PC/Desktop/TV/Home Stereo, etc. TF Card Playback 【2-in-1 Bluetooth Receiver + Transmitter】 This Bluetooth adapter has both Bluetooth transmitter and Bluetooth receiver functions, allowing you to easily switch between transmit and receive modes. In transmitter mode (TX mode), you can transfer audio from non-Bluetooth devices such as TVs and notebooks to Bluetooth speakers and Bluetooth earphones. In receiver mode (RX mode), you can convert traditional non-Bluetooth devices (legacy speakers, amplifiers, car speakers, and other wired devices) into Bluetooth devices, pairing them with mobile phones and tablets to wirelessly transfer music. 【Bluetooth 5.4 & RGB Ambient Light】 This Bluetooth transmitter & receiver adopts advanced Bluetooth 5.4 technology, reducing lag and delay, smoothing audio transmission, and delivering high-fidelity sound quality. TF Card Playback Supported Unlike other Bluetooth transmitters on the market, this 3.5mm Aux Bluetooth adapter supports TF card playback in both receiver and transmitter modes. Insert the TF card into the adapter. Bluetooth Receiver Mode: Transmit music to home speakers, wired earphones, wired acoustics, etc., via the 3.5 mm AUX interface. Bluetooth Transmitter Mode: Transmit music to Bluetooth devices such as Bluetooth earphones and Bluetooth speakers via the Bluetooth adapter. Music files in the TF card can be easily read and played, supporting many common music formats such as MP3, WMA, APE, WAV, and FLAC.