Hot Car MP3 Player FM Transmitter Modulator with USB SD Slot. Support MP3 and WMA music playing; Support SD card. Memory functions of song, volume and frequency. Plays the music in flash memory, and transmits to radio. Support memory function when power off. Play the music automatically when you insert the 12 volt adapter end into your vehicle's cigarette. This car USB MP3 player is also play your audio devices wireless through your car stereo, such as MP. Turn your car stereo on and tune the frequency to the same as your car MP3 player, press the play. Buy this and Save 30% Off on Car MP3 Player FM Transmitter Modulator at Coolicool.com. Get Worldwide Free Shipping.