2-in-1 Design: In TX mode, the Bluetooth transmitter is plugged into non-Bluetooth devices such as TVs, PCs and MP3 players via AUX/RCA jack and transmits audio to Bluetooth headphones/speakers/soundbars; in RX mode, the Bluetooth receiver can be connected to wired speaker/earphones and to receive audio from smartphones via Bluetooth Stable Connection, Stereo Sound: Equipped with a built-in Bluetooth 5.4 chip, not only helps to upgrade your old audio devices to Bluetooth capable without replacing them but also promises you a CD-like auditory feast. Seamless Streaming: With low latency, the audio delay has been minimized, it will present fully synchronized audio and video Working While Charging, Nonstop Fun: The built-in battery can support the Bluetooth adapter to work for long hours per full charge. When in the low battery status, the adapter could be plugged into power to get charged while working at the same time Specification: Features: Support U disk /TF card (card not included) Product size :12x44x60mm Audio interface: 3.5mm AUX Transmission distance: ≤10m Bluetooth version: 5.4 Material: ABS material Transmission mode: receive/transmit signal Battery capacity: 200mAh