Product specification: ● Product name: USB Bluetooth FM transmitter ● Product model: FM02 ● Bluetooth version: V5.3 ● Working voltage: 5V ● Operating range: within 10 meters ● Output: FM transmitter ● FM frequency range: 87.5MHz–108MHz ● Default frequency: 95.0MHz ● Signal-to-noise ratio: ≥95dB ● Call answering: supported ● Auto reconnect: supported ● Power supply: USB powered (5V) Package includes: 1 x USB Transmitter Receiver Features: 1. Upgraded to Bluetooth 5.3 for stable and fast wireless connection 2. Built-in display screen for easy operation 3. Equipped with 3 control buttons to adjust FM frequency (87.5–108MHz), volume up/down, and track navigation (next/previous) Interface and Button Functions: USB interface: Used for power supply. Connect to any standard 5V USB port, such as a car USB port or car charger with 5V output. Multi-function M button: 1. FM frequency adjustment: Long press the M button until the screen flashes to enter FM adjustment mode. Use the '+' and '-' buttons to adjust frequency. Press M again to confirm and exit. 2. Play/Pause: During music playback, press M to pause or resume. 3. Answer/End call: Press M to answer an incoming call or end a call. Multifunctional '+' and '-' buttons: - '+' button: Press to skip to next track; long press to increase volume. In FM adjustment mode, use to increase frequency. - '-' button: Press to go back to previous track; long press to decrease volume. In FM adjustment mode, use to decrease frequency. Instructions: 1. Plug FM02 into a 5V USB port in your car. 2. Use the M button to set the desired FM frequency. Turn on your car radio and tune it to the same frequency as FM02. 3. FM02 automatically remembers the last used frequency. On power-up, it will default to that setting. 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. For best sound quality, set your phone’s volume to maximum and adjust listening level using your car’s volume control. Avoid setting car volume too high to minimize noise and distortion. Precautions: 1. The default FM frequency is 95.0MHz. If interference occurs, adjust to a clearer frequency. 2. Some car models disable the built-in USB port when the radio is on. If FM02 does not power on, use a car charger plugged into the cigarette lighter socket (ensure 5V output). 3. For optimal performance, especially in vehicles with factory USB ports that cause interference, use a separate car charger via the cigarette lighter. 4. FM02 does not have an auto power-off feature. 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 phone, and try again.