This is an incredibly high frequency SOS Whistle. The sounds that emits from the whistle is loud and crisp with little effort needed to reach the frequencies needed for you to be found. The distance the sounds travels is ridiculous for its size.
Great for calling for help, recruiting companions or wild-life alerting.
Another awesome feature is that it can be hung anywhere a key ring can go. For example your tent, water bottle, equipment's or backpacks. You'll never be without it!