Specification: Product model: SFD-FM02 Bluetooth-Compatible version: V5.3 Working voltage: 5V Effective distance: within 10 meters Audio output: FM transmitter FM frequency range: 87.5MHZ-108MHZ Default frequency: 95.0MHz Signal to noise ratio: ≥ 95db Answer phone calls: Supported Automatic backflow connection: /> Power mode: USB power supply (5V) Product size: about 32 * 17 10mm/1.25 0.66 0.39inch Gross weight: 9g Button Description: Multi function M button: 1. adjust the press and hold,button screen will start flashing enter adjustment mode. Long or short "+" "-" buttons quickly slowly adjust. After is,completed click,confirm stop flashing. 2. When playing a,song pause playback. 3. Answer call: someone,calls you can call. Multifunctional buttons Instructions: After setting find Bluetooth-Compatible pairing name settings your pair. music played by be car's speakers. 5. Adjusting volume: phone's adjusted its maximum Adjust moderate level. not recommended up too,much as higher more severe distortion. Attention: 4. does have shutdown function. unplug from searched paired searching,clicking clear previously connected devices restart try again. Note: Due different monitor light,effect actual color item might slightly showed pictures. Thank you! Please allow 1-2cm measuring deviation due manual measurement. 1 x Car FM Transmitter Receiver 1. Latest Bluetooth-Compatible Technology: The USB FM Transmitter is designed for car scenarios and features the latest Bluetooth-Compatible 5.3 technology and mature frequency modulation technology, allowing car enthusiasts to easily enjoy wireless music in their cars. 2. USB Interface for Power: The transmitter can be powered by a USB interface. When in use, you can plug the transmitter into a USB port with an output voltage of 5V, such as a car's USB port (5V) or car charger port (5V). 3. Upgraded Version: The FM02 USB Adapter is an upgraded version of the FM01 with 3 additional buttons for adjusting channels from 87.5 to 108, volume control, and track selection. The Bluetooth-Compatible version has also been upgraded to Bluetooth-Compatible 5.3 and includes an LCD display screen. 4. Good Compatibility and No Lag: The mini USB adapter has good compatibility, no delay, and no stuttering. It is compatible with almost all cars and phones on the market, making it easy to use and access. 5. Satisfaction Guarantee: We strive to provide each customer with the highest standard of customer service to ensure you have a pleasant shopping experience. If you have any issues, inquiries or need assistance, please feel free to contact us directly.