Kleinn Air Horns Add to Cart Kleinn 20-24 Chevrolet Silverado 2500 HD/ 3500 HD Onboard Air System w/ Model 730 Horns - GMHD20-734 MSRP: $1,689.94 Was: Now: $1,299.95 Kleinn Automotive Accesories is a U.S. manufacturer of extremely high quality air horns, train horns…