Kuba whistle (E), and United States Coast Guard (U. Small size. Coast Guard) are used to product the same type and high reputation and trust from related distress, rescue, fire, security agency. The whistle is 二穴 construction and sound for generating sound, make you more far less than different radio frequency whistle in case of the Sharp, fluid and one hole for what you get. Super when you check the position · Warning in emergencies, disasters is a perfect for your confirmation. In addition, when mountain climbing, hunting in distress and prevent harm beasts as a necessity for your cell phone.