For flash memory (USB only): 1) Plug FM modulator into vehicle\'\'s 12V adaptor 2) Plug you flash memory into FM modulator\'\'s USB port 3) Adjust the channel setting it the signal is interfered in your area (87.7, 87.9, 88.1, 88.3, 88.5, 88.7, 88.9MHz), or (106.7, 106.9, 107.1, 107.3, 107.5, 107.7, 107.9MHz) 4) Tune your car stereo to the same FM frequency as the FM modulator 5) Press the play button on the FM modulator 6) Music / audio transmits to vehicle\'\'s stereo system 7) Press the forward >>| or back, | track at a time. Hold these buttons down to increase and decrease the signal output For using with MP3, CD, or DVD players: 1) Plug FM modulator into vehicle\'\'s 12V adaptor 2) Using the audio cable, plug you MP3, CD, DVD player or other audio device into the FM modulator\'\'s stereo jack 3) Select one of the 7 FM modulator presets that a local radio station is not broadcasting on (87.7, 87.9, 88.1, 88.3, 88.5, 88.7, 88.9MHz), or (106.7, 106.9, 107.1, 107.3, 107.5, 107.7, 107.9MHz) 4) Tune your car stereo to the same FM frequency as the FM modulator 5) Press the play button on the FM modulator 6) Music / audio transmits from player to vehicle\'\'s stereo system. For using audio frequency: 1) Integration computer design, FM modulator with memory stick (memory stick not included) 2) It can be charge to MP3 / PDA / and Mobile in directly 3) The audio frequency have input and output hole. Plug the common MP3 player or any other portable instruments. Such as CD / VCD / DVD / MD / PDA into the cigar outlet (12V), you will be surely satisfied with device enjoying high performance music Specifications: 1) Operating range: >10m 2) Operating current: 45mA 3) Transmission range: 87.5 MHz - 108.0MHz (interval 0.1MHz) 4) Frequency response: 20 - 15,000Hz 5) Stereo separation: 40dB 6) Transmission frequency deviation: 7) Frequency stability range: ±10PPM 8) Signal-to-noise ratio: ≥68dB