This dual tone air horn is powered by a compact compressor and is very loud. Installation is easy because this horn runs off of the electrical system of any 12 volt vehicle. The compact compressor design allows for installation into very tight spaces. The Airmax 2 has two durable red plastic trumpets and a maintenance free compressor. Comes complete with all mounting hardware, and installation instructions. Designed for durability, this unit will provide many years of dependable service.