The Storm whistle is the loudest whistles in the world, capable of being heard over a half mile away and even able to work underwater. Easy to hold, easy to use and easy to hear. The Storm whistle is used by Police, military, search and rescue teams and industrial safety personnel as an alarm and personal. The Storm whistle works by utilizing a resonance chamber attached to the whistle that enables the whistle to focus its sound like a laser beam and blast a noise twice as loud as any whistle made in the world. This same harmonic chamber also acts to protect the whistle from mud, snow, sand … even water. Proudly made in the USA.