Sonic Air horns for Boating, Industrial Safety, Sporting Events, Distress Signaling canned air horn,high pressure horn 400ml power canned airThese compressed air signal horns are the best we've found, and we've looked! They're 100% non-flammable, emit no CFCs. Ideally suited for industrial safety, personal safety, marine & wilerness outings, sporting events & emergency signaling for any reason. ...