Orion 1oz Boat Air Horn This marine signaling air horn meets United States Coast Guard requirements for boats up to 39 in length. This 1oz air horn is able to provide up to 12 blasts per can with a 112db blast at 10. This easy to use horn is a perfect marine signaling device. Air Horn Operation Do not shake before or during use Screw the horn onto the cartridge It will snap into place around 3 turns Hold in the upright position Depress the button in a series of short blasts NOTE Long continuous