specification : This is a MP3 player special used in a car. It can download MP3/WMA/WAV/WMV/ASF Formats file from the computer directly and save it in the inside flash memory. It is used high quality MP3 decoder chip decode MP3/WMA files from inside flash memory to audio signal then through Fm transmitter chip change FM signal and transmit it and play high quality music by FM radio of car. Appurtenance: Instruction, USB data connector for downloading, warranty card, USB version supported: USB1.1/USD2.0 Decoded file format: MP3/WMA/ASF Memory Capacity: 128M/256M/512M/1G are all optional Transmit Band: FM Frequency Channel: 87. 7/87. 9/88. 1/88. 3/88. 5/88. 7/88. 9 MHz. Transmit distance: 3-9M for internal antenna, Output Audio Frequency Response: 20HZ-20KHZ Output Frequency SNR: >90DB Power Supply: DC9-15V Working Temperature: -20~60 Centigrade How to use 1) Use the data cable attached to connect computer, when you see the ICO of USB disk, you can download files from the internet or copy MP3, WMA etc. files to this USB disk. 2) Plug the player into the car lighter, and make sure the DC voltage is 9~15V. 3) Press the 揅H?key-switch and turn the launch frequency to any one (87.7MHz. to 88.9MHz.) 4) Press the "Play" Button for three second, the green LED on, then the player goes to stand-by. 5) Turn on your car audio equipment and switch it to FM.; Car audio keeps Mute when searching the proper frequency. Make sure the receiving frequency is same as the transmit frequency. 6) Press the "Play" Button lightly and the green LED changes to flash quickly, when the player turns to "Play" state, the Car Audio can search the music signal of transmission of this machine.