Our Bluetooth Dual USB Port Fast Car Charger built-in dual USB output, USB port support smart charging, it is available for charging most kinds of devices in car. LCD display of frequency and voltage. The Bluetooth Dual USB Port Car Charger support SD/TF memory card and USB flash drive reading, can play music files on MP3/WMA/APE/FLAV/WAV format. With a support of FM channels, this Car MP3 Wireless FM Transmitter lets you take a break from your regular music. Plug the MP3 player into the cigarette lighter of your car directly, easy to use and carry. Features: Dual USB 3.1A charging battery voltage detection. Support Bluetooth music / TF card / U disk playback, support Bluetooth hands-free calling. Orange LED screen for displaying frequency, song number and working status information. 2 mobile phones are charged at the same time, support while listening to songs and charging. Noise cancellation function, built-in noise cancellation circuit, making the call sound clearer. Support folder switching playback function, song classification and playback Support power-off memory function. Specifications: With voice prompts LED frequency display. Dual USB outputs 5V/4A Frequency :87.6-107.9MHZ; Supports MP3/WMA format files; Supports TF card / USB flash memory; Build in MIC , Hands-free talking and A2DP music playing Switch to Hands-free mode automatically from music playing Car battery voltage display : to examine your car battery condition NOTE: Flash Drive and Mini USB Card is just for illustration purposes , so not included in the package.