Product specification:● Product name: USB Bluetooth FM transmitter● Product model: FM02● Bluetooth version: V5.3● Working voltage: 5V● Effective probability: within 10 meters● Audio output: FM transmitter● FM frequency range: 87.5MHZ-108MHZ● Default frequency: 95.0MHZ● Signal-to-noise ratio: ≥95db● Answer the call: support● Automatic return: support● Power supply mode: USB power supply (5V)Package includes:1 X USB Transmitter ReceiverFeatures of our USB Transmitter Receiver:1. Bluetooth version upgraded to Bluetooth 5.32. Added display3. Add 3 buttons to adjust the channel from 87.5 to 108, volume up and down up, and down the song.Interface and KeyUSB interface:The USB interface is used for power supply. When using it, you can plug this product into the USB interface with an output voltage of 5V, for example, the car comes with a USB interface (5V), and the car charger interface (5V).Multi-function M button:1. To adjust the FM frequency, long press the M button, and the screen starts to flash to enter the FM adjustment mode. Long press or short press the '+' and '-' buttons to adjust quickly and slowly. After adjusting, click the M button to confirm, and the screen stops flashing.2. When playing a song, click the M button to pause and play.3. Answer the call: When someone calls in, you can click the M button to answer the call.Multifunctional '+' and '-' buttons:1, '+' button: click the next song, long press to increase the volume, in the FM adjustment mode, click and long press to adjust the FM channel.2, '-' button: click on the previous song, long press to reduce the volume, in the FM adjustment mode, click and long press to adjust the FM channel.Instructions:1. Plug FM02 into the USB interface in the car with an output voltage of 5V.2. Set the FM frequency band through the multi-function M button, then turn on the car radio, and adjust the FM frequency band of the radio to be consistent with that of FM02.3. FM02 has FM frequency automatic memory function, every time it is powered on, it will default to the FM frequency of the last use.4. After the FM frequency band is set, find the Bluetooth pairing name: FM02 in the Bluetooth settings of the mobile phone, and click to pair. Then the music played by the mobile phone will be played on the car's speakers.5. Adjust the volume: When you are playing music, you can adjust the music volume of the mobile phone to the maximum, and adjust the car volume to a moderate level. It is not recommended to turn up the car volume too much, because the louder the car volume, the more serious the noise and distortion will be.Precautions:1. The default frequency band of FM02 is 95.0MHZ, which can be used directly. If there is a lot of playback noise, it can be adjusted to other frequency bands.2. When the radio of some models is turned on, the car's built-in USB interface will be powered off. At this time, if the FM02 is plugged into the built-in USB port, it cannot be used. In this case, you can plug the FM02 into the use of the cigarette lighter and car charger. The power supply is used on the interface (the output voltage of the USB must be 5V).3. FM02 is used in some original cars with USB interfaces, which may be too noisy or unusable. It is recommended to plug FM02 into the cigarette lighter car charger for use.4. FM02 has no automatic shutdown function, it is recommended to unplug it from the USB interface when not in use.5. When the FM02 cannot be searched in the Bluetooth settings of the mobile phone or cannot be paired after being searched and clicked, it is recommended that you clear the previously connected Bluetooth devices in the mobile phone, and then restart the mobile phone and try again.