A pair (2) of brand new Heavy Duty 12 volt Air Compressors. Designed for tight engine compartments and motorcycles. It is compact in size 4.5" Height x 2.5" Diameter, all metal housing. Produces a powerful 15 psi each. Mounts easily with a built-in mounting tab. This Model is universal and can be used for all one (1), two (2), and three (3) trumpet small air horns that operate on a direct drive compressor. comes with positive (+) and negative (-) electrical terminals for easy installation. Will replace your old worn out air compressor, so you can get the maximum sound out of your air horn.