Features: 1) Frequency: 87.7 - 107.9MHz 2) Preset 4 channels 3) Audio frequency range: 50Hz - 15kHz 4) Operating range: 10 - 30 feet 5) Power light and frequency LED indicator 6) Dual power models: BAT or exit DC power supply 7) Rechargeable circuit: DC 5V 8) Operation introduction: a) Plug FM transmitter into your music player b) Set FM transmitter and your radio to the same FM frequency c) Turn on the FM transmitter and the music player d) The music will be transmitted from the player to the FM radio wirelessly e) Enjoy your music now 9) Note: for best results, select a frequency that has the weakest or no signal from radio stations