Product Specifications● Product Name: USB Bluetooth FM Transmitter ● Bluetooth Version: V5.3 ● Working Voltage: 5V ● Effective Probability: Within 10 meters ● Audio Output: FM Transmitter ● Default Frequency: 95.0MHZ ● Signal-to-Noise Ratio: ≥95db ● Answering Calls: Supported ● Automatic Return: Supported ● Power Supply: USB Powered (5V) Package Contents: 1 X USB Transmitter Receiver Our USB Transmitter Features of Receiver: USB Interface The USB interface is used for power supply. When in use, you can plug this product into a USB interface with an output voltage of 5V, such as: the car's own 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 flashing to enter the FM adjustment mode. Long or short press the "+" and "-" buttons for fast and slow adjustments. After the adjustment is completed, click the M key to confirm and the screen stops flashing. 2. When playing a song, click the M key to pause and play. 3. Answer a call: When someone calls, you can click the M key to answer the call. Multi-function ''+'' and ''-'' buttons 1, ''+'' button: Click the next song, long press to increase the volume, in FM adjustment mode, click and long press to adjust the FM channel. 2, ''-'' button: Click the previous song, long press to reduce the volume, in FM adjustment mode, click and long press to adjust the FM channel.