The Windstorm All Weather Safety Whistle out performs other whistles in loudness, in all weather conditions and safety situations. On land, it can be heard up to 1.5 miles and can even be heard under water, up to 50 ft. A high impact non corroding thermoplastic protective housing is easy to grasp. The double chamber design allows it to be blown when held right side up or upside down forcing, all water to be purged when the whistle is blown. Out performs other whistles in loudness. Can be heard up to 1.5 miles away over land, and under water to a depth of up to 50 ft. High impact, non corroding thermoplastic construction. Double chamber. Lanyard ring.