Bests & Worsts Reviews from Amazon

I've bought multiple Fox 40 whistles, emergency boating whistles and aluminum British police style whistles. This whistle is by far the loudest whistle I have ever heard. I do a lot of mountain biking on trails alone, so I like the safety factor of having a really loud whistle and a really bright LED flashlight with strobe and SOS modes in case I get injured biking and am too hurt to hike out of the woods. I also bike on multi-use trails, with joggers, walkers, dog-walkers and even horses sometimes. I don't try to spook horses, but many joggers and walkers wear stereo in-ear earbuds (I never bike with earbuds in, because it's way too dangerous), so if I'm coming up behind someone, especially with a dog, I try to give them a heads up as far away as possible with a quick whistle toot, because it's too easy to startle a human or a dog that is not realize you are rapidly approaching from behind, and if you are riding at 20-25 mph, it's not very hard to stop if they jump in your intended path at the last moment. Each of the two whistles I got seem to to have slightly different pitch. One seems like both chambers are perfectly matched in pitch, and one seems like the two chambers have a slightly different pitch. But they are both REALLY loud. My 2 whistles came with a bonus 3rd mini aluminum single chamber whistle. Not nearly as loud as the two main whistles, but super small and light, so I keep it attached to my car keys. I'm very satisfied with my purchase.