Use this unit to change audio signal into frequency modulation signal by full frequencies and transmits wireless to the stereo in the car or at home and play, every frequency between 88.0 to 108.00 can be chosen. Operating Range: up to 10 meters Power Output: 0 -300mW Power source: 2 AAA batteries Sound: Stereo sound, digital stereo encoder completely built-in Stereo separation: 72 DB Frequency control: Dual speed phase locked loop (PLL) How to use 1. Install 2 AAA batteries in the battery compartment of the unit. 2. Plug the connecting cable to the headphone jack of your MP3 or MD/CD/VCD/DVD player. 3. Tune your car stereo or receiver to the clearest FM frequency from 88. 0MHz -108. 0MHz 4. Hold (^) and (v) for two seconds to turn on the unit 5. Press (^) or (v) to select the channel same on the radio 6. Enjoy the beautiful digital music with full stereo sound 7. Hold (^) and (v) for two seconds to turn off the unit Memory Frequency Function: There are 5 memory date that you can store the clearest frequency for convenient operating. To store the frequency in memory: 1. Press (^) or (v) to select a clear frequency between 88 - 108. 0 MHz. 2. Press the memory buttons (mem). 3. The frequency is stored. To play the music from the memory frequency: Tune your car stereo or receiver to one of the memory frequency Select and press the memory button on FM transmitter. Enjoy the music.