What horn is this?

[PBC_Tacoma_Kid]

I am looking for a horn setup for my truck, I have heard them on some unlimited cars ( I think maybe the Wilson bros). The sound is more like an emergency vehicle/cop car sound. Almost sounds like a loud buzzing rather than a high pitch horn. Is it electric or air? Who makes it?
I found a sound clip similar to what I want.
http://www.audiosparx.com/sa/play/play.cfm/sound_iid.29702

Thanks Brandon

[la2baja]

The emergency siren comes with the horn you are talking about. It is a buzzing sound. These are not legal for use on the street but can be purchased. Not sure where. Just don't use it to get a cop out of your way. That would be bad!

[younggunracer]

I cant ever hear horns anyways. Luckly I am usally driving fast enough to not get passed(of course) or I get lucky and there always happens to be two lanes when a faster car reaches me.

[4oshun12]

Go to Galls.com, its a police type magazine and that's an air horn that we have on out units, im sure you can find something there