. Play mp3/wma audio file in USB disk. . with built-in stereo wireless transmitter, There are 206 frequencies for you selection, Ranging from 87.5HMZ to 108.0 MHZ,0.1MHz interval. . LED display frequency, Song number, volume and EQ parameter. . The current song, volume, frequency and EQ parmetercould be memorized when turn off the power by press(play/pause key) .4 buttons support previous track, next track, volume adjust, frequency selection, play and pause with infrared remote control. . Can provide 7 EQ mode. . With an audio input interface of stereo device. . vehicle's cigarette lighter receptacle power supply:DC 12V-24V.