ACMEGenuine Professional Quality BPA Free Plastic No. 636 Tornado AIRFAST Whistle, Slimline, Small Sized, High-Pitch, pealess, 122 dBA, Designed and Made in The UK. White

After reading many whistle reviews, I bought several different whistles to test. This is the loudest small whistle I tested, and the 3rd loudest of all of the whistles I tested. The loudest whistle was the Storm STORM® Safety Whistle and the 2nd loudest whistle was the Windstorm Windstorm Safety Whistle. The Storm & Windstorm required the least hardest blowing effort to get a loud sound, and the Acme 636 only required a moderate blowing effort to achieve a loud sound. Also, the Acme 636 required the least blowing effort of any of the small whistles to be able to get a loud sound. I recommend the Acme 636 Safety Whistle to anyone looking for a SMALL safety whistle.UPDATE: I need to say that over the years my high range hearing has been damaged to the point where it no longer exists. Whistles that I rate poorly MAY be loud to people with full range hearing, but the whistles I rate highly all have a lower frequency which I can easily hear. Something to think about; hunters and other people who have been exposed to very loud noises, like gunshots, may have damaged high range hearing, and may not hear your high pitched whistle. Whereas pretty much everybody can hear a lower pitched / lower frequency whistle. Plus, if I'm injured (think of a fall resulting in broken ribs)I will not be able to give my whistle a hard blow, so for me to rate it highly it must be LOUD without having to blow it hard.

Very suitable for my needs with the compact size. Have not had to use it; hope I never do....

I read reviews that raved about how good this is for an emergency whistle; but it makes a wimpy sound. I can't imagine anyone being rescued using this whistle.

I got one for me and for each of my daughters to keep on our keychains. I told them it's a safety whistle, but my one daughter called it a rape whistle. It's white and pretty and made in England and is a small investment that could someday save a life. Wasn't Rose's life saved by a whistle in Titanic?

Love that this is thin and flat, I keep it as a back up when I'm reffing.

Lightweight, very loud. Perfect for a college student backpack for added safety walking campus at night.