2-in-1 Bluetooth Audio Adapter: In TX mode, the Bluetooth transmitter can be plugged into non-Bluetooth devices such as TV via AUX/RCA jack and then pair it with your wireless headphones. Start enjoying music or watching videos without disturbing others. In RX mode, connect it to the audio port of your wired speakers via 3.5mm/RCA cable, and pair it with your smartphone. In this way, you could enjoy high-quality music wirelessly | Perfect Synchronization: Equipped with the latest mature Bluetooth 5.0 chipset and well-designed software, this technology not only helps to upgrade old audio devices to Bluetooth without replacement, but also provides you with the ability of a CD-like listening feast | Dual-link: ZIOCOM Bluetooth Transmitter receiver can be paired with two headphones in TX mode, which can satisfy the idea of watching movies with your lover.You can also pair two mobile phones in RX mode to switch songs from different mobile phones at any time | Long Play Time: Built-in 250mAh rechargeable battery,10H long endurance.And the Bluetooth audio transmitter receiver can continuously working while powering，enjoy your favorite wireless life as long as you can | Compatibility Notes: The Bluetooth audio adapter can be connected via 3.5mm AUX cable and RCA cable. If your device is a fiber optic interface, please buy our other products with fiber optic interface | PLEASE NOTE: 1. There is a built-in battery, you'd better turn it off after using it and you need to turn it on when use it next time. 2. You can not answer calls through it because of no built-in microphone