I bought this onboard air system for my Jeep Wrangler to power a 24" Grover half horn I bought from a junkyard. It only took me about 50psi to get the horn sounding good, but pumping 80-120psi out of this little thing just makes it explode! I am very happy with this purchase, the tank and the compressor work perfectly. Not only does it power my half horn, but it also has a separate tank mount so you can pump up tires etc on the go!