I've seen these before and now I want my own. They're basically horns that are placed outside of your car that can blare deafening music. Now what sets this aside from the average Loud horn or speaker or whatever is that they play music from your mp3 player. Most I find online play 1-3 pre-set songs. My friend told me he got his horns for $10 each at the flea market but surly its not that simply. How would you connect it to your stereo? I don't know. Just need some insight I guess. Btw this will basically be for throwing parties outside, although it should not matter what they will be used for.