RX Mode Pairing :1. Turn on the device. Blue light flashes quickly.2. Then turn on the phone Bluetooth setting and search for Bluetooth device to select and pair connections.3. Insert the 3.5mm audio into the RX port to connect the transmitter and receiver device.4. You can enjoy the wonderful musicTX Mode Pairing:1. Turn on the device.2. Then turn on the receiver device (Bluetooth speaker, Bluetooth headset, and other Bluetooth enabled audio system ) and wait a few seconds. The device will connect with the BT transmitter automatically.3. Then insert the 3.5mm cable into the TX port and your transmitter device (MB, TV, PC, MP3/MP4 those don’t have the Bluetooth function).4. Finally, you can enjoy the music.The Indication Light:1. the red light doesn't flash when you charge.2. the red/blue light flashes quickly when the device is on transmitter/receiver modern and don't pair successfully. the red/blue light flash slowly means pair 4.2,A2DP, AVRCP (receiver mode only)Operation Range:Up to 10m / 33ft (without any blocking objects)Charging Time: 2 hoursContinuous Use Time: 6 hours (Receiver Mode) / 5 hours (Transmitter Mode)Battery Type: Li-Polymer (200mAh)Dimensions: 44 × 44 × 12mm/1.73 x 1.73 x 0.47inchPacking List:1-100* Bluetooth V5.0 Audio Transmitter/Receiver AdapterBuyer Note:If you are satisfied with our service, we appreciate you leaving us a positive response and 5 star rating review! Your opinion is important to the success of our business. If you are not satisfied with the product or have not received the product for more than 35 days, please contact us to resolve, we will do our best to solve. We are sure to come up with a satisfactory solution. Please contact us first before leaving cold response or good response of 1-3 stars and opening the case. We'll do our best to solve your problem. Because we believe that everything can be solved through communication. Thank you very much！