This complete air horn assembly measures 15 inches in overall length with a 4 inch diameter bell and a 1/8 inch pipe port for connecting to the truck’s air system. It includes the FRK-4089 rebuild kit components, giving it everything needed for a full replacement rather than just a bell or valve swap. It fits Mack cab and chassis setups where the horn mounts to sound a compressed-air warning to pedestrians and other drivers.Interchanges:38MR359BFeatures15 in. overall length4 in. diameter bell1/8 in. pipe portIncludes FRK-4089 rebuild kitTech SpecsOverall Length: 15 in.Diameter: 4 in.Pipe Port: 1/8 in.Rebuild Kit: FRK-4089