Aptx & Aptx Low Latency: Powered by a premium chipset, this 2-in-1 wireless audio transmitter and receiver supports Aptx and Aptx Low Latency in both TX and RX modes. Enjoy movies with synchronized wireless audio and no noticeable delay. TX Transmitter Mode: Wirelessly stream stereo audio from non-Bluetooth sources like TVs, MP3 players, CD players, PCs, or e-readers to your Bluetooth headphones, speakers, or receivers. Enjoy high-quality music wirelessly without disturbing others. Note: This Bluetooth adapter does not have a volume control button. RX Receiver Mode: Transform your old wired headphones or speakers into Bluetooth-enabled devices. Enjoy wireless, CD-like audio quality from your home stereo or wired speakers. Charge While Using: The built-in battery supports 8-10 hours of operation per full charge. Dual Streaming & Multipoint: In TX mode, pair the transmitter with two Bluetooth headphones or speakers and stream audio to both simultaneously. In RX mode, pair with two phones or tablets, but only receive audio from one at a time. Note: Codec downgrades to SBC when pairing two BT devices simultaneously. Compact & Portable: Weighing only 14 grams, this round Bluetooth transmitter is compatible with most Bluetooth headphones. Easy to store at home and take on trips or flights. Note: The Bluetooth adapter is primarily for RX mode in cars.