1.Clear Sound and High Call Quality: The FM transmitter With advanced interference and noise cancellation technology (CVC technology) the product can create full duplex sound and get rid of noise. 2.USB Car Charger: With the Car Charger, you can keep your devices fully charged while driving. Ideal for mobile users with an active, on-the-go lifestyle,this charger plugs directly into your car's DC power connector. 3.Hands-free Calls:The Kit provides convenient wireless connectivity with excellent audio quality for calls and music. The buttons make it effortless to control.Easy to adjust FM frequency, play previous or next song, answer, hang up or reject a call, etc. Specifications: Wireless Version: V4.1 + EDRFM Frequency: 87.5~108.0MHzProduct Input: 12-24V Charging output: 5V/3.4ARead U-disk & SD card: 1G-32GB CSR Chipest for nice sound Hi-Fi FM Transmitter Product Features: -CVC technology to control noise and storm then to create full-duplex sound quality -Support external USB port, can play MP3/ WMA format music files -2 USB ports for both playing music and quick charging -Hands-free calling with voice reminder -Start the car, the screen will display the car batter voltage. -Memory function for auto Wireless connecting once paired -Sound quality-Using the most advanced interference and noise cancellation technology to provide the most perfect sound quality.