The Ocean Alert Mini Dual Trumpet Air Horn is constructed of solid brass and has a bright chrome-plated finish and stainless steel base plate. The compact size of this horn is ideal for smaller boats, while the horn still produces a warning sound equal to larger horns. Designed with Lexan noncorrosive diaphragms to provide years of dependable service in salt or freshwater environments. The heavy-duty 12V compressor is also compact in size for easy installation and is maintenance-free. Complete air horn kit includes compressor, rubber gasket, hose, 30-amp relay, and stainless steel mounting hardware. Wolo Model 160 Ocean Alert Mini Dual Trumpet 12-volt DC 127 decibel rating 525/630 Hz Horn: 9.5″L x 5″W x 3.75″H Compressor: 4.5″H x 2.25″ dia.