Well I was gonna mount these on my trk, but Im installing a fuel cell where they would have been mounted. Horns are Air Chime, 5 gal Campbell Hausfield tank, pressure switch, switch and compressor. And yes they really loud and do indeed work.
If you do a search I posted a vid of what they sound like.
$200
Im SW of Houston
http://i129.photobucket.com/albums/p...S/IMG00054.jpg