"If you feel you're getting more Wi-Fi interference than other iDevice users in your area (considering that if you're in an area with a lot of open networks, a small amount of this type of interference could be normal behavior), you can take a few steps to troubleshoot the problem and reduce the interference you are experiencing."
20 X 9 mm blue backlight LCD display, clear reading of the tuning frequency
Full frequency range, effectively avoids signal interference
Automatically pauses playing music when calls incoming
Max 10 meters wide effective transmitting range
Powered by iPhone / iPod directly, no need extra power
Suitable for iPhone 3G, iPhone, iPod Classic / Touch / Nano
http://www.6deal.com/en/car-fm-transmitter-charger-for-apple-iphone-3g-ipod-nano-touch-classic.html