This portable, lightweight wireless audio transmitter and receiver is the ideal wireless audio solution for every situation and application, and can be used with computers, mobile phones, televisions, home speakers, and car speakers. Use the latest Bluetooth 5.0 technology, fast transmission speed, high-quality stereo music, enjoy the convenience of Bluetooth technology for life. Specifications Model: KN330 Technologies: BT5.0, A2DP, AVRCP (receiver mode only) Operation Range: Up to 10m / 33ft (without any blocking objects) Pairing name(Receiver mode ):KN330 TX:Transmitter mode,red LED light is on RX:Receiver mode,blue LED light is on Dimensions: 45mm*20mm*11mm Specifications: Mode switching: Use the TX/RX switch to switch modes.TX is the transmission mode(red LED).RX is the receiver mode(blue LED) There is no built-in battery, and it is powered by DC 5V usb interface Insert usb power, the red light is on in the transmitting mode, the red light flashes when pairing, and the red light is always on after the pairing succeeds. Insert usb to power on, the receiving mode is blue light, the blue light flashes when pairing, the blue light is always on after pairing is successful. Use for computer: When you use it on your computer. No need audio cable and no driver required, plug and play (only audio can't transmit data). How to use: Switch to the transmitting mode (TX), the red light flashes, and the Bluetooth speaker or Bluetooth headset is turned on at the same time, it will be automatically paired. After the pairing is successful, the red light will be on. Use for other devices: When used on other non-computer devices with audio output, such as a TV How to use: Plug one end of the audio cable into the audio output of the TV and the other end into the audio of the KN330. Plug the KN330 into the usb (DC 5V) and confirm that it is in TX mode (red light flash). The KN330 will automatically search for Bluetooth headset or Bluetooth speaker pairing. Use for home speakers/ car speakers, etc KN330 can help home speakers, wired headphones, car speakers, etc. without Bluetooth. Bluetooth connection with your phone. how to use: Plug one end of the audio cable into the audio output of the speaker and the other end into the audio of the KN330.