Equip your truck with the Kleinn 412 direct-fit single chrome-plated roof-mount air horn system, featuring a single premium 25-inch chrome-plated stainless steel trumpet equipped with a unique rectangular opening and protective horn cover to keep road debris out of your system. Engineered for universal semi-truck and commercial vehicle applications, this heavy-duty roof-mounted configuration allows you to command the road with a deep, authentic, and loud over-the-road big-rig blast. Designed for clean external mounting on custom or commercial rigs, this high-performance horn kit features a 1/4-inch airline input that requires an onboard pressurized air system and can be operated using a manual hand-pull air valve or an electronic solenoid valve. For a proper, leak-free setup right out of the box, the installation requires a Model 330 Roof Mount Air Horn Fittings Kit, providing the ultimate balance of glistening chrome style and serious acoustic presence that heavy-duty custom truck builds count on.