1. This outdoor multi-functional three-in-one whistle is a practical item for outdoor travel and competition activities. 2. It is made of good-quality ABS material, which is sturdy and durable and can adapt to various complex outdoor environments. The overall weight is only 16 grams, making it light and easy to carry. Whether you are on a hiking trip, mountain climbing adventure, or participating in various competitions, you can carry it easily without adding extra burden. 3. This whistle integrates three practical functions. First, it has a whistle function with a loud and clear sound. In case of an emergency outdoors, it can be used to send out a distress signal to attract others' attention; in a competition, it can convey instructions in a timely manner. Second, it is equipped with a compass, which provides reliable assistance for you to identify directions outdoors, so you don't have to worry about getting lost. In addition, it also has a thermometer, which can display the surrounding temperature in real-time, facilitating you to adjust your clothing and activity plans according to the temperature changes. 4. In terms of specifications, this three-in-one whistle is exquisitely designed, perfectly integrating three functions into a small object. It is suitable for a variety of scenarios and can meet the actual needs of outdoor sports enthusiasts and professional people such as competition referees. With it, your outdoor journey will be more worry-free and convenient, and the organization and conduct of competitions will also be more efficient.