Parameter: 1. Product model: BT-350 2. Product material: plastic + metal 3. Product color: black 4.Interface type: 3.5mm 5. Bluetooth version: Bluetooth 5.0 Instruction for use: I. Power on / off (1) Switch on: Press and hold the on / off button for 3 seconds until the blue LED light starts to flash. (2) Turn off the power: Press and hold the on / off button for 5 seconds. The red LED indicator will light up and then go out. Note: Read the user guide of the transmitter or mobile phone to learn how to turn on / off Bluetooth wireless technology. 2. Pairing If this is your first time using this device, please configure it first. (1) To enter pairing mode, press and hold the on / off button (button1) for 5 seconds until the red and blue LEDS flash. (2) Search for a music receiver on your phone or compatible transmitter. Touch and hold a button to turn on the power and it will automatically search for compatible transmitters; if connected to an compatible with Apple or Android device, you do not need to enter any code, and the LED light below the button indicates the device and charging status. (3) The devices should now be able to identify and pair with each other. After successful pairing, the LED on the music receiver will slowly flash blue. (4) To complete pairing, some devices require a password or passcode, please enter "0000". (5) After successful pairing, you can power off the device. To reconnect, just power them on, and you don't need to pair them again. Note: If you want to use the music receiver with another transmitter, you must restart the pairing process with the new device from the first step. After pairing a new transmitter, the old transmitter will no longer be paired with the music receiver and only one device can be connected at a time. 3. Play music (1) Connect the music receiver to the auxiliary (AUX) input of your home or car stereo using the supplied audio cable and adapter. (2) Make sure that the transmitter (mini jack, mobile phone, PC, PAD or compatible signal source) is turned on and paired with the music receiver, and the distance between the devices is not more than 10m. (3) The blue LED on the music receiver will flash slowly, indicating that it is connected. (4) Press "Play" and the music will be sent to the music receiver wirelessly. 4.Charging (1) Connect the little end to the mini-USB input of the music receiver using the supplied USB cable. (2) Connect the other end to the USB input of the PC, laptop or USB power converter. The LED of the music receiver will light red during charging. (3) After charging is completed, the red LED will go out. Provides up to 6 hours of playback time when fully charged. 5. Handsfree (1) By default, your phone uses a Bluetooth microphone, and the phone for a speaker phone is MIC. (2) Phone, you can press the button (button 1) to answer the voice call. (3) After the call is over, the phone will automatically enter the auto-entry state. (4) Disconnect after one minute and the Bluetooth device will be turned off. High-tech wireless product for seamless audio streaming Receives music via mobile phone, TF card, or Bluetooth transmitter Compatible with almost all audio receivers with input plugs, including automotive equipment Stream music from your smartphone or MP3 player to home speakers or car audio systems Features an embedded echo cancellation microphone for clear calls