Full Frequency FM Transmitter. Digital Display. Supports Line In Audio input. With power off switch (USB direct connect). Supports U Disk TF memory card. Supports MP3 music. Can handle mobile phone calls (answer;hang up;reject;redial and other functions) through Bluetooth. Supports Bluetooth stereo music play as well. Comes with Echo cancellation and noise. Supports USB output voltage for charging devices with maximum output of 5V/2.1A. Automatic power off memory funtion.