Kleinn Air Horns 230 Triple Train Horn - Black Three Trumpets, 17.5-Inches, 15.5-Inches and 11.5-Inches Deep, Loud Train Horn Sound Requires 150-PSI Onboard Air System (Not Included) Vortex 4' 12 Volt Electronic Train Horn Solenoid Included Up To 153.3 Decibel Output (156.9 Decibel With Blastmaster Upgrade Kit)