Features of the Storm Whistle include:

-Can be heard underwater up to 50ft
-Unique patented design allows it to be heard even under water
-Sounding chamber forces all water to be purged when the whistle is blown
-The Storm whistle is twice as loud as any other mouth-blown whistle in the world
-Survival bright yellow color, orange, or black
-Creates a clear, high frequency sound, with a power rating over 75% greater than other referee and safety whistles
-The Storm® All-Weather Safety Whistle is the loudest whistle in the world
-It's perfect for divers, lifeguards, SAR, and for recreation
-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
-Even for someone who is short of breath. Responsive - Emits the loudest sound with minimum effort
-Adopted by the US Military, police and security forces worldwide!
-Be safe, be found. U.S. Military approved. The Storm Whistle is a must have for any emergency situation when you need to be heard.