Outdoor Hiking, Traveling, Camping, Climbing, Cycling or in a Dark Environment, this Whistle can be used to ask for help, remind others, or scare away wild animals.</br></br> The combination of two different materials of whistle meets all your needs for whistle:</br> Plastic whistles: high-impact plastic material, durable, compact and not easily broken. Even in the cold in winter, it will not freeze and stick to the lips and can float.</br> Aluminum whistles: metal material, sturdy and durable, waterproof, rustproof and fireproof. It will not crack or freeze under harsh conditions.</br></br> Common features:</br> 1. The sound is loud and not harsh.</br> 2. The material is sturdy and durable, waterproof and rustproof, not easy to break.</br> 3. Small, compact design, easy to carry.</br> 4. It is easy to sound.</br> 5. Convenient access-it can be hung on clothes or pants pocket/belt/backpack. In addition, it is equipped with an adjustable rope. You can choose to hang it on your neck or other easy-to-reach places.</br> 6. Classic and fashionable appearance, no matter where you choose to put it, it will not appear obtrusive and outdated.</br></br> Place these whistles in different places and carry them with you. Each person should be equipped with two life-saving whistles during outdoor activities, one with them, and one with a backpack, just in case. It can also be used as a small gift for relatives and friends who like to exercise.</br></br> Wide range of applications</br> Suitable for any water sports, boating, swimming, playing football, fishing, cycling, hiking, tourism, hunting, climbing, camping, training birds or dogs, etc.