Product specification: ● Product name: USB Bluetooth FM transmitter ● Product model: FM02 ● Bluetooth version: V5.3 ● Working voltage: 5V ● Operating range: within 10 meters ● o output: FM transmitter ● FM frequency range: 87.5MHz–108MHz ● Default frequency: 95.0MHz ● Signal-to-noise ratio: ≥95dB ● Call answering: supported ● Auto return: supported ● Power supply mode: USB power supply (5V) Package includes: 1 x USB Transmitter Receiver Features of our USB Transmitter Receiver: 1. Bluetooth version upgraded to Bluetooth 5.3 2. Added display screen 3. Includes 3 buttons to adjust channel from 87.5 to 108, control volume up/down, and skip tracks Interface and Key Functions: USB interface: Used for power supply. Connect to any 5V USB port, such as a car USB port or car charger with 5V output. Multi-function M button: 1. To adjust FM frequency, long press the M button until the screen flashes to enter FM adjustment mode. Use the '+' and '-' buttons to adjust frequency quickly or slowly. Press M again to confirm and exit. 2. During playback, press M to pause or play. 3. To answer a call, press M when a call comes in. Multifunctional '+' and '-' buttons: 1. '+' button: Press to skip to next track, long press to increase volume. In FM adjustment mode, press or hold to adjust FM frequency upward. 2. '-' button: Press to go to previous track, long press to decrease volume. In FM adjustment mode, press or hold to adjust FM frequency downward. Instructions: 1. Plug FM02 into a 5V USB port in the car. 2. Use the M button to set the desired FM frequency. Turn on the car radio and tune it to the same FM frequency as FM02. 3. FM02 has automatic frequency memory. Upon power-up, it will revert to the last used frequency. 4. Enable Bluetooth on your phone, search for device named "FM02", and pair. Once connected, o from your phone will play through the car speakers. 5. Volume adjustment: Set phone volume to maximum and adjust car stereo volume to a comfortable level. Avoid setting car volume too high to minimize noise and distortion. Precautions: 1. The default frequency is 95.0MHz, which can be used directly. If interference occurs, switch to another frequency. 2. On some car models, the built-in USB port may lose power when the radio is turned on. If FM02 stops working, use a cigarette lighter adapter with 5V USB output instead. 3. In some vehicles with factory USB ports, performance may be affected by interference. For best results, use with a cigarette lighter car charger (5V output). 4. FM02 does not have auto power-off. Unplug it when not in use. 5. If FM02 is not detected or fails to pair, clear previous Bluetooth pairings on your phone, restart the device, and try again.