[Features]
1. Lightweight and equipped with a keychain for easy carrying;
2. Larger caliber, louder whistle, essential supplies for outdoor help;
3. Aluminum alloy material, the surface is made of anodizing technology, does not fade, and has a longer service life.
Survival whistle use range: The survival whistle does not have to be used when in distress, such as saying hello to the front and back, determining how far away it is, determining which direction the other party's sound source is, etc 
