Kleinn Air Horns 99 Dual Air Horn - Chrome-Plated Zinc Alloy Dual Air Horn Trumpets, 8-1/2 Inches And 6-1/2 Inches High Pitch, Painful Sound Chrome Plated Zinc Alloy Air Horn Trumpets Requires 150-PSI Onboard Air System (Not Included) Up To 153.6 Decibel Output