MPC Train Air Horn Kit; Three Oversize Flat-Rack Trumpets, 130 PSI Compressor & Tank Flat Rack Mount Triple Train Horn w/ 12 volt electronic solenoid. Overall Horn Dimensions: 19.5" x 17.5" x 5.5". Trumpet Lengths: 16.25", 14", 12". 130 PSI All-in-one Air System. Compressor Dimensions: 24"L x 5.25"W x 6.75"H. Tank Capacity: 1 gallon. Pre-mounted pressure switch and tank fittings Air line, push-button & mounting hardware Free Wiring Kit!