This Loud Train Sound Air Horn is made entirely of metal, Triple Chrome Plated to withstand all weather conditions. Comes with a 1.5 air tank, 150 PSI 12 volt Heavy Duty Air compressor, air pressure gauge, pressure switch, mounting hardware, hose, fittings, installation instructions, and a FREE horn button. Air horn system will produce a very loud train sound at 149 decibels, and surely will get anybody's attention around you. Great for SUV's, trucks, RV's, pick-ups, marine use and many more applications. Horn dimensions: 13-3/4", 11-1/2", 9-1/4", 7-3/4" . Tank/compressor dimensions: 16" L x 11-1/2" H.