The transmitter comes with a small cable 3.5 jack to one side for the MP3 player and 2.5 of one for the transmitter input. And a remote, small and very well adapted to its use, it includes features not found on the transmitter, its use is highly recommended. For twenty euros, I find that this model works very well and helps perfectly to get good sound when you have no possibility of anything other than the radio in his car. Of course the ideal is that the cigarette lighter is located in a place that can properly read his screen, which although very small, has information at a resolution which makes them very legible. In terms of frequency, simply take a few minutes and sweep the frequency ranges of the radio to find an available channel and free of any radio reception. The instructions advise where necessary to unscrew the external antenna to avoid having an improved radio reception and thus avoid the potential interference. As for me, a few minutes were enough to scan find a correct channel. The sound: although sometimes means a breath between songs, I find that the transmission is good, its correct interference and the rare or nonexistent. The sound spectrum is quite good, without being a lightning war. One tiny catch: the equalizer with preset modes do not lead to flagrant changing the sound spectrum, it is so minimal that it is hardly noticeable. That said, the sound is quite good, and for twenty euros, it was worth the money. No frills in functions, everything is there. Only regret the supplied cable is a bit short if one chooses to use a sound source solution through this one.