Review on 📢 Wolo 419 Bad Boy Air Horn - 12V, Black by Jason Bell

To be clear, if you are buying this for a car you will not need an additional wire or harness. A car or truck has enough power to plug directly into the existing wiring. It supports single or two wire installations. The horn comes with a relay. If you are buying for a motorcycle you will need a wiring harness not a relay as it comes with the horn. I bought it for my Jeep, I already have two horns in JK but this one is louder. It was a close landing.