**Bluetooth 5.4 & Lower Latency:** Equipped with the latest Bluetooth 5.4 smart chip, this Bluetooth transmitter/receiver offers superior audio decoding technology, ensuring up to 99% low latency. This maximizes the restoration of the original sound, delivering high-fidelity stereo sound quality comparable to CD-level standards. **Multifunction Transmitter/Receiver:** In TX mode, connect non-Bluetooth audio sources, such as airplanes, TVs, or MP3 players, to Bluetooth-enabled speakers or headphones via a 3.5 mm (AUX/RCA) cable. In RX mode, receive audio from a smartphone or other Bluetooth source device and transmit it to non-Bluetooth wired speakers or car/home stereos. **TF Card Mode:** When a TF card is inserted: 1. The Bluetooth adapter can transmit signals to connect wireless headphones or stereos to play audio from the memory card. 2. It can connect bidirectionally with devices without Bluetooth functionality, such as stereos, cars, and wired headsets, via a 3.5mm interface cable to play audio from the card. (NOTE: The TF card is not included and must be purchased separately). **HD Screen:** The Bluetooth adapter features an LED screen that provides real-time battery capacity and volume information, eliminating the need to estimate battery life or volume levels. It also displays paired devices (e.g., headphones/AirPods model name), TX/RX/TF Card mode, and audio format (e.g., SBC/AAC/aptX-HD/LL/AD). This user-friendly design enhances your audio streaming experience. **Safety First and Wide Compatibility:** The Bluetooth audio transmitter meets global quality standards and is certified by FCC, CE, RoHS, BQB, and more. It ensures safety with features like voltage endurance, overcurrent, short circuit, and NTC overheat protection. Its compact size, powerful 4-in-1 capabilities, and the latest Bluetooth 5.4 smart technology provide the highest quality audio transmission, allowing you to immerse yourself in the audio world anytime.