Wireless In-Car Bluetooth FM Transmitter MP3 Radio Adapter Car Fast USB Charger Product Features: 100% brand new and high quality. Multifunction: constructing with FM transmitter, hands free talking, FM radio, car charger and FM displayer. Hands-free phone call: built-in microphone, noise and wind suppressed by CVC technology create full duplex sound quality, allow you to make clear calls. Wider range: full FM radio frequency ranges from 87.5 to 108.0MHz, you will get a frequency without interference more easily and do not have to keep re-tuning it. Dual USB ports: One is designed for transmitting and reading the MP3 files automatically, the other supports charging compatible with Bluetooth enabled devices, like iPhone, iPad, tablet, Samsung and other smartphones. Monitor battery status: detect and display the voltage of car battery when power on. Multi protection: overcurrent protection, overvoltage protection, short circuit protection, overpower protection, over temperature protection. Memory function: automatically connect to its memorized paired Bluetooth device when power on. How to Use: Plug FM Transmitter into the cigarette lighter socket. Turn your car FM radio station and search the frequency (87.5MHz~108.5MHz) same as the device with name of T20. Long press the function key for 2s to enter the frequency-adjustment interface. Rotate the function key or fast-forward key and fast-backward key to adjust the emission frequency. Then long press the function key for 2s to confirm and exit. Match it to the transmitter. Button functions: Play/pause: press call button to play, press again to pause. Adjust volume: long tap right volume key to up the volume, long tap left volume key to down the volume. Select frequency: long press call button 2s enter main menu, rotate knob to adjust, click to confirm. Tap right volume key to increase frequency, tap left volume key to reduce frequency. Select music: press right volume key to play next song, left one to play previous song. Answer/end call: press call button to answer call, press again to end call; click left volume key to reject the incoming call, double click call button to redial. Specification: Type: Handsfree Bluetooth Car FM Transmitter Kit Bluetooth version: V3.0+EDR Sensitivity: -42db+/3db 360 Voltage: 5V+/-0.5 Working current: 45mA (max) Standby current: 25mA (max) Frequency: 2.402-2.480ghz Effective range: 5V Sensitivity: -92dBm RF output: 4dBm FM: 87.5MHz-108.0MHZ Transmitted power: 87 dBuv/107 dBuv Effective range: 5m Dimension: 1.85*1.97*3.43in (47*50*87mm) Weight: 1.26oz (36g)  Package Includes: 1 x Bluetooth Car FM transmitter Kit 1 x User Manual