Broadcast your music while charging your iPhone or iPod MP3 player Transmits stereo quality sound from your portable music player to your car FM radio. Transmits on 4 preset FM channels ranging from 88.1-88.7 MHz Just tune your car radio to one of the 4 preset channels , adjust the FM Transmitter to the same radio frequency, plug FM Transmitter's into iPhone / ipod port and then it's done. Just sit back and enjoy! Features Power and charge your iPhone / iPod simultaneously through the 30-pin dock connector Flexible Clamp: Holds electronic devices securely with the padded arms High quality silicone gel on back and sides protect your device from being damaged Specifications Frequency Channels: 88.1 / 88.3 / 88.5 / 88.7 MHz For best sound performance, please set your MP3 player's volume level to MEDIUM. Then use your car stereo's volume control to adjust the output level. Compatible with:All models of Apple iPod with Dock Connector including: iPod Touch / iPod Touch 2nd Generation / iPod Classic / iPod Classic 120GB / iPod nano Gen3 / iPod Nano 4th Generation / iPod 5G [Video] / iPod Nano / iPod Photo / iPod Mini / iPod 3G/4G / iPhone 3G