The TuneCast is a pretty simple device. It's pretty much a long cable with a car 12V connector (aka cigarette adapter) at one end, an iPod dock connector at the other end, and a control module in the middle. It's pretty long, and I found that passengers in the backseat of my car can control my iPod, even with the TuneCast plugged in at the front console. It should be noted that the TuneCast needs to be plugged into a 12v jack otherwise it doesn't work.
The front control module has a big screen showing it's tuned frequency, memory status, and audio enhancement status. It's easy to see during daytime and nightime. There are three buttons on the front: two buttons for tunning up/down FM frequencies, and one button for a feature called Clearscan. In Belkin's words, "Cut through the static with ClearScan. Avoid the frustration of manually finding a clear FM station. ClearScan technology quickly scans and finds the best FM frequency--all with one push of a button."
The top of the control module has three buttons. The buttons labelled M1 and M2 allow you to switch between two saved frequencies. By holding down the buttons, you can save the currently tuned frequency in that respective memory location. The Pro button toggles between three different sound optimization filters (and turning the filters off).
When M1 or M2 are selected and they contain FM frequencies, the screen indicated Memory 1 or Memory 2, respectively.