1) With FM radio music transmitter 2) MP3 decoding: decdoes MPEG 1 and 2 audio layer 3 (ISO11172-3), supporting VBR for MP3 3) FM modulation: selective 7 channels, within 87.7-88.9MHz 4) FM transmitting power: 10mW 5) FM transmitting distance: 3-5m 6) Audio input sensitivity: -10dBv 7) Isolation between left and right sound channels: >40dB 8) Response frequency: 20-15kHz 9) Internal memory: N/A 10) Audio souce: external USB storage device (such as USB drive, card reader) 11) USB version: USB 1.1/2.0 compatible 12) Power supply: cigarette jack, DC12V 170mAh 13) Buttons: play/pause, next, prev, FM channel switch 14) LED: flash when reading music form USB drives