The Roadmaster 15" 110 psi Dual Air Horn is designed to produce a loud and distinctive sound that can be heard from a long distance away. This air horn is made from quality materials to ensure reliable performance and long service life. It is designed to produce a loud sound of up to 125 decibels and a frequency of 238 hertz. This air horn is perfect for a wide range of applications and can be used indoors and outdoors. With its 4" flare and 110 psi, this air horn will surely get the attention of anyone in its vicinity. FleetPride is your First Click in Heavy Duty®.