2-in-1 Transmitter & Receiver: Adds Bluetooth to TVs, speakers, car stereos, and more via 3.5mm AUX. Bluetooth 5.4: Stable, low-latency connection—perfect for TV, airplane entertainment, or home theater. Hands-Free Calling: Built-in mic with noise cancellation for clear calls and voice navigation. Dual Modes + TF Card: TX Mode: Stream audio from TV/PC to Bluetooth headphones. RX Mode: Receive audio from phone to wired speakers or car stereo. TF Mode: Play music directly from TF card. Long Battery Life: Up to 5 hrs (TX) / 8 hrs (RX) on a single charge. Can be used while charging.