The Marinco FullBlast compressor driven air horns are the loudest and most complete line of 24V air horns available. All of our air horns produce sound levels ranging between 120 and 127dB, which means all of our air horns meet the ABYC and NMMA regulations for boats up to 20 meters/66 feet. Non-corrosive Lexan polycarbonate diaphragm Includes compressor, air tubing, fittings, and hardware Dimensions: 17″ L x 7″ W x 3.75″ H Maximum amp draw: 12 volt: 20 amps, 24 volt: 10 amps dB rating: 121 at one meter, 1/3 octave band Fundamental frequency 375+/-15Hz, 315+/-15Hz