Specification: Bluetooth: V5.0 Audio Port: 3.5mm Material: ABS How to use? Completely wireless USB receiver or transmitter mode. (Driverless plug and play) Bluetooth AUX Receiver or Transmitter Mode (No battery required. Powered by USB) Mode Switch: Switch between transmit mode and receive mode. It is very simple as follows: (1) TX mode---red light: plug in when you see the red light flashing, means TX mode, if no red light, you plug it in and plug it out again, it will turn red. ligh(2)RX mode---blue light: plug in when you see blue light flashing, means RX mode, if no blue light. You unplug it and plug it back in, it will turn into a blue light. Package includes: 1 Bluetooth transmitter and receiver, 1 3.5mm audio cable, 1 user manual, Bluetooth 5.0 Bluetooth receiver and transmitter 2 in 1: USB to Bluetooth adapter is for not - bluetooth car tv, pc home stereo, when it is in bluetooth receiver mode, you can use it as a car speakerphone become a bluetooth speaker and enjoy music streaming from your smartphone tablet or other bluetooth device, when it is in Bluetooth transmitter, you can use it, easy to use and swith modes: This bluetooth adapter is very easy to use and swith modes. No batteries required, plug and play. RX MODE: plug in and with flashing blue light, you can use it with cell phone or tablet; TX MODE: Plug and unplug, then plug again, you can see RED light, it means TX mode, you can use it for TV or laptop and pair with Bluetooth speakers or headphones. High Quality Sound: Durable design with Bluetooth. Version 5.0, it can bring you high quality sound, you can enjoy streaming music in your car or anywhere you like Small and simple: This car bluetooth adapter is very small and simple, also very easy to use , no battery needed, USB. Port plug and turn on, unplug and turn off. It is a best gift for you and your friend. It is a great choice for you. The Bluetooth transmitter function wirelessly streams audio to Bluetooth speakers or headphones from your TV or older media devices such as portable CD players that lack built-in Bluetooth.