From what I can see they're showing this in the same category with 12 volt car MP3 transmitters. This is definitely not in the same category, which shows Amazon either doesn't check items listed for accuracy or they don't care if it's illegal as long as they can make a buck off of it, and I tend to believe the latter.
I can see a need for something like this for small coverage areas, but the power level is definitely way too high and illegal. But these are probably sold to people who don't know or don't care that it's illegal.