The Long Horn is an air powered system that produces a powerful big rig truck sound. Two durable red plastic trumpets belt out a blast that cannot be ignored. Installation is easy on any 12 volt vehicle. The heavy-duty compressor is maintenance free and is powered by your truck's electrical system, so you do not need to hook-up your air supply. If you want a horn for your vehicle that will produce a that big truck sound, the Long Horn is a perfect choice. Comes complete with all mounting hardware and installation instructions. Includes one 11 5/8" trumpet and one 12 1/8" trumpet.