Loud Train Sound Air Horn is made entirely of metal in black color. Comes with a 1.5 (6 liter) air tank, 150 PSI 12 volt heavy duty Air compressor, air pressure gauge, air pressure switch, mounting hardware, hose, fittings, Teflon tape sealer, installation instructions, and FREE horn button. This Air horn system will produce a very loud train sound of 152 decibels, and surely will get everybodys attention around you. Great for SUV, truck, RV, pick-up, boat and marine, and many other applications. Air tank/compressor dimensions: 16" L x 11-1/2" H. Air horn dimensions: L 19 1/4" x W 18" x H 7.5".