A full train horn onboard system, ready to install. In this package, the intense quad trumpet air horn, Black color, made entirely of metal for maximum protection against all weather conditions. This system includes a 1 Gallon air tank, 150 PSI 12 volt air compressor, pressure gauge, pressure switch, hose, fittings, horn button and mounting hardware. Ideal for all vehicles with a 12V system. A bold, loud choice.