Package Included: 1x Bluetooth 5.0 Audio Transmitter/Receiver Adapter 1x 3.5mm Aux Cable 1x User Manual Specification: Technologies: BT5.0, A2DP, AVRCP (receiver mode only) Operation Range: Up to 10m / 33ft (without any blocking objects) Pairing name(Receiver mode ):KN320 Transmitter mode: red LED light is on Receiver mode: blue LED light is on Dimensions: 32mm*17mm*8.5mm Features: This extremely portable, lightweight wireless audio transmitter & receiver is an ideal wireless audio solution for a wide range of situations and uses1. This extremely portable, lightweight wireless audio transmitter & receiver is an ideal wireless audio solution for a wide range of situations and uses Transmitter mode：wirelessly streams audio from your non-Bluetooth TV, home stereo system, or CD player to your Bluetooth headphones or speakers Receiver mode： wirelessly streams audio from your Bluetooth-enabled phone, tablet, or computer to your wired stereo, speakers, or headphones Mode switching: a) First plug the product into the USB port to power on. b) When the time after power-on is within 10 seconds, you only need to re-plug once to switch modes. c) When the time after power-on exceeds 10 seconds, you need to re-plug twice to switch modes. Note: This product has been used for more than 10 seconds and will remember the mode. It will be the last mode when it is powerd on next time. 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. How to use: a) Receiving mode: used in home audio, wired headphones, car audio, etc. without Bluetooth.How to use: Power on the product and confirm the receiving mode (blue light), open the Bluetooth settings in the phone and tablet, search for the pairing name: KN323 for pairing, connect the home audio, headphones, car audio with 3.5 audio cable Wait. b) Transmitting mode: Use on TVs, computers, mp3s, etc. without Bluetooth. There is no need to install the driver, but it needs to be connected with 3.5 audio cable. It can only transmit audio and cannot transmit data. How to use: Power on the product and confirm the transmitting mode (red light). The product will automatically search for the Bluetooth headset, Bluetooth audio, Bluetooth receiver and other devices next to it. The KN320 just 32mm (1.26”) across and weighs only 3.2g (0.11oz), but has got powerful wireless audio streaming capabilities. Slip this transmitter & receiver into your backpack or laptop bag and take it on-the-go without the slightest effort. Broad Compatibility: With the included 3.5mm cable, this Receiver Transmitter adapter can widely be used on your computer, laptop, home stereo system, headphone, smartphone, Mp3 player, CD player, etc. Note: Please allow minor deviation due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item.