I am a physical education teacher so a whistle can be my best friend when the need arises. This whistle is not only loud but the sounds emitted from it are controllable. Since the whistle is high pitched, even a small bit of air pushed through the mouth piece can be enough to grab the attention of my students. On the other hand when emergency scenerios come up a full blow on this whistle will stop everyone in their tracks. I would definitely recommend this whistle. Although, I didn't like paying 7 dollars for the whistle, I followed the reviews on this page and bought it anyway. I still thought after buying it that I was foolish to have spent close to 10 bucks including shipping on a whistle, but I realized after I received it, my money was well spent, and I will never purchase any other whistle then this one in the future. It is worth the extra money!