Marinco Trumpet Air Horns 12V Chrome Plated dual trumpet air horn is made of solid brass construction with non-corrosive Lexan polycarbonate diaphragm Includes compressor, air tubing, fittings, and hardware Maximum amp draw: 12 volt: 20 amps dB(A) rating 121 at one meter, 1/3 octave band. Meets the ABYC and NMMA regulations for boats up to 20 meters/66 feet. Fundamental frequency 375+/-15Hz, 315+/-15Hz