Kleinn Air Horns HK7 Complete Triple Train Horn System - Black Features 'Beast' Model 230 Train Horn; Horn System With 150 PSI Air System 3-Gallon Air Tank (Five 1/4-Inches NPT Ports) 150-PSI Rated Air Tank Made in the USA All Mounting Equipment and Hardware Included Features 'Beast' Model 230 Train Horn; Horn System With 150 PSI Air System 150-PSI Rated Air Tank Made in the USA All Mounting Equipment and Hardware Included