Overview: Hight fidelity, stereo, digital PLL LCE display Output:88.1-107.9 M Hz, 0.1 M Hz/ Step Small electric current, power supply by iPhone 3G. With Car charger, & it can be charged to iphone 3 G Compatible:iPhone nano, touch 2, nano 4, iPhone 3G, touch, nano 2, classic, nano 3, iPod shuffle, iPhone shuffle. Operating Instruction:1. Connect transmitter to iPhone 3G, select the suitable frequency.2. Press on " "/"-" button to your desired frequency, then adjust your tune radio to the same frequency.3. Plug car charger into car cigarette adaptor, & connect car charger to fm transmitter, then it can be charged to iPhone 3G & transmitter at the same time. Specification: Weight Approx:47.5g Size Approx:4.3 x 2.9 x 2