One of the Kahlenberg “Zero Series” range of air horns, the S-0A Air Horn is certified to international requirements (IMO COLREGS) for boats up to 65 feet (20 Meters) in length. Made entirely of bronze and brass, the S-0A is constructed for a lifetime of marine service. The S-0A requires significantly less air to achieve high dB levels and can be powered by extremely small compressed air systems to minimize associated cost and space requirements on board.