Review on 100W Police Air Horn Amplifier With Manual Control, Stock Horn Bypass, And Waterproof Design - Ideal For Emergency Vehicles, Trucks, And Cars With 100W Speaker Compatibility by Carlos Whitfield

Hooking this up is very simple. once you have 12v and ground, there is one factory wire you need to splice, which is the horn relay wire. Very simple. My car required an extra relay, which I did not know about, because my horn is controlled by ground. This is a simple enough deal, to wire in an additional relay, but would have been nice to know about before hand, as now I have to wait 2 days for the relay. Their customer service tech line was able to inform me of this, and very quickly point me to what I need, so no issue.