Features: 1. Easy to Use: Bluetooth-compatible version: 2.1. There is no need to install any software, plug and play. 2. Wireless Bluetooth-compatible: The TV sound is transmitted to the home combined speaker through Bluetooth-compatible, so there is no need to worry about the trouble caused by wiring. 3. Enjoy the Music: By transmitting TV sound to Bluetooth-compatible headset through Bluetooth-compatible, you can enjoy the shocking sound effect alone in the dead of night without worrying about disturbing others. 4. Wide Usage: This Bluetooth-compatible transmitter is not only suitable for home use, but also for classroom speeches and conference speeches. 5. High Performance: Speak directly to the product's Mark air outlet, and you can transmit the speech sound to the Bluetooth-compatible speaker. There is no need to worry that is too small to be heard by others. Specification: Interface: USB Wireless Type: bluetooth-compatible WIFI Standard: None Content: AUDIO High Definition Support: None Model Number: Audio Transmitter Support paired Bluetooth-compatible stereo headset/headset to control play/pause, forward/backward Support automatic pairing (no keys) Support pairing pin code: 123400008888 Frequency range: 2.42 to 2.480 MHz (analog) spectrum Working current: 40mA maximum Compatible with 30PIN Operating range: 10m Material: plastic colour: black Package Contents: 3 x Bluetooth Audio Transmitter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.