Equip your vehicle with the Kleinn HK4-1 complete direct bolt-on ProBlaster quad black air horn and onboard air system, featuring four tuned zinc alloy trumpets measuring 13 inches, 11 inches, 8.5 inches, and 7 inches in length with 3-inch bell ends. Engineered for universal application, this premium truck horn configuration leverages additional trumpets to deliver a more fully-blended, devastating chord while remaining compact enough to fit inside almost any car, truck, or sport utility vehicle. Providing the pneumatic power is a Model 6270RC 130 PSI waterproof electronic air compressor paired with a generous 1.0-gallon all-steel air tank equipped with an internal Cortec anti-corrosion coating to provide maximum blast time. Designed for a clean, professional, and seamless installation, this complete standalone package comes right out of the box with a pre-wired Vortex 4 Series Model 307 electronic solenoid valve, a 1/4-inch high-pressure airline, a 12-volt relay, a pressure switch, and all necessary mounting hardware to ensure long-lasting durability and a stealthy, high-performance aesthetic on any custom build.