Product Specifications: Model: SY318 Bluetooth version: 5.0+EDR Operating Range: Up to 10m/33ft (without obstacles) Transmitter mode: red LED light on Receiver mode: blue LED light on Mode switch: click the button Product size: 45*20*9.5mm Product net weight: 5g Product gross weight: 15g Packaging accessories: 1* 5.0 bluetooth receiver transmitter 1* AUX audio cable 1* Chinese and English manual Pairing steps: This product is plug and play, no driver required A: Launch mode - red light 1. Plug the device into the USB port for power supply, switch to the launch mode, the red light flashes, and enter the state of automatically searching for Bluetooth devices (such as Bluetooth adapters, Bluetooth headsets, Bluetooth speakers), etc.; 2. Insert one end of the 3.5MM audio cable into the AUX interface of the adapter, and the other end into the audio output hole of the TV, projector, tablet computer, MP3, CD player and other equipment or the RCA audio signal output hole of the TV; 3. Turn on the Bluetooth device and adjust it to the pairing state. The pairing is successful and the red light is always on. Note: The computer is plug-and-play, driver-free, and no connection required (only audio can not transmit data). If there is no sound, please set the sound as the sound card output in the sound settings. Different Bluetooth devices (such as Bluetooth headsets) have slightly different search connection times due to differences in the schemes and protocols used, which is normal. If the pairing fails or cannot be connected for a long time, you can turn off all the devices and then restart the pairing again. B: Receive mode - blue light 1. Plug the device into the USB port for power supply, switch to the receiving mode, the blue light flashes, and enter the wireless receiving state (when the computer is powered on, first plug the cable into the product, and then plug the product into the computer); 2. Insert one end of the 3.5MM audio cable into the AUX interface of the adapter, and the other end into the audio input interface of the playback device (such as headphones, speakers, cars, etc.), or plug the 3.5mm audio cable of other playback devices into the audio port of the device. 3. Turn on the bluetooth function of the mobile phone or tablet, automatically search for bluetooth devices, select "RT-09" in the bluetooth list and click to pair, the blue light is always on after the pairing is successful. Note: You can also directly insert the device into the read U disk interface of the player to realize the Bluetooth function. When the connection is successful and there is no sound, please delete the device that has been paired successfully, there may be a Bluetooth device conflict.