The New Wind Storm Safety Whistle for water sport safety This incredible whistle features: Can be heard underwater Unique patented design allows it to be heard even under water, up to 50 feet Sounding chamber forces all water to be purged when the whistle is blown The Wind Storm whistle is twice as loud as any other mouth-blown whistle in the world Wind Storm quality product Survival bright yellow color, orange, or black Safety Whistle for all water sports and personal safety The Wind Storm All-Weather Safety Whistle is the loudest whistle in the world Over 94 decibels! Perfect for survival and earthquake kits, military, police, hunters, sporting events, divers, lifeguards, etc! Creates a clear, high frequency whistle sound, with a power rating over 75% greater than other safety whistles or referee whistles Dual chamber quickly purges for uninterrupted sound High-impact thermoplastic Be safe, be found. U.S. Military approved. The Wind Storm whistle is used by U.S. Coast Guard, Washington, D.C., NFL Referees, many Police departments including New York Police Department, Special Forces, Red Cross.