Viking Horns V301K-2C Three Trumpet Loud 139 Decibels Air Horn With Dual Air compressors Sound output: 139 decibles Construction: Metal base with 3 Chrome plated trumpets 2 Heavy duty 12 volt air compressors Trumpets Sizes: 11.5", 9", 6.5", with 3-3/4" diameter each Includes hardware and installation instructions