This Package Includes: Chrome Double Air Horns 12v Electronic Air Solenoid Mounting bracket and mounting hardware SEE PICTURE BELOW FOR INSTALLATION DIAGRAM Want to make some MAJOR noise, but only have a little room? These train horns can fit in almost any vehicle and deliver the big sound you are looking for. Dont be tricked by their size they may be small but they pack a blast that can make others envious. These are loud, heavy duty, long lasting horns. The finish on them is not perfect, don't expect them to be flawless for your "show truck" But a great deal for this nice, heavy duty set. Air Horn Specifications: Overall Dimensions: 11.5" x 6" x 3.75" Trumpet Lengths: 9.75" and 7.75" Trumpets Bell Width: 3.5" DB output: 120 db Construction: Chrome plated zinc alloy Requires air compressor and tank (not included)