Hi-Powered 4 Trumpet Train Air Horn And Compressor/Tank kit. Horn system produces a Loud Sound of 149 decibels. Trumpets are chrome plated metal. Will replace your original horn, or can be installed as an auxiliary horn. Comes with a 1.5 gallon air tank and 12 volt 150 PSI heavy duty maintenance free air compressor. Includes Mounting Hardware, Brass Fittings, Air Tube, Air Valve, 240 PSI Air gauge, 150 PSI Air Pressure Switch, installation instructions. Ideal for vehicles such as Truck, RV, SUV, Boat and more. Horn trumpet sizes: 13-3/4", 11-1/2", 9", 71/2", 3-3/4" front diameter each. Air compressor dimensions: 9-1/2" L x 4" W x 6-3/4" H. Air tank dimensions: 15" L, 7-1/2" H.