Eco-Blast Sport Air Horn - $17.88

Use any bicycle pump, air compressor or local service station to refill this environmentally-friendly air horn. One charge puts out more than 40 blasts of sound at 115db. It meets all U.S. Coast Guard regulations and conveniently fits in a drink holder. Noncorrosive and nontoxic because it uses no chemicals and no batteries, just compressed air. - $17.88