red kk I'm the only one with an airhorn in a KK that i know of, i can give u some advice but what type of horn did you want... train horn and air horn are two different things... train horns are huge, literally there would be no place to put them besides under the jeep, where u have to worry about them getting damaged from road debris or if you offroad forget it. your going to need some type of OBA to get that loud desired sound... how loud depends on the PSI and the size of your tank.. you will also need a compressor and a solenoid. I can show you which brand i got... you need to buy a few other things but it's not too bad... Mine's pretty loud, hooked to a switch so when i hit my regular horn it fires with the regular horn( which you don't even hear cause the airhorn is so loud) and fires the regular horn when the switch is off