PREMIUM MATERIAL - This emergency whistle is made of high-quality aluminum alloy. Waterproof, sturdy, and durable. The surface is anodized and will not fade. Its surface is smooth and does not easily adhere to dust. It can be used for a long time. DOUBLE TUBE DESIGN - The double tube design provides a louder and clearer sound. It can be heard from a long distance without having to strain to blow. The excellent airflow design allows for use in all weather conditions. Nothing can get jammed. It allows you to be easily heard in an emergency situation. HIGH DECIBELS - This emergency survival whistle with two tubes can provide you with up to 120 decibels of sound. It has a fantastically loud and clear sound. It can be heard from a distance and can be perfectly used as a signal whistle or rescue whistle. LIGHTWEIGHT & PORTABLE - The emergency survival whistle weighs only 10 g and measures 5.7 x 1.5 x 0.8 cm. Lightweight and convenient to carry. It comes with a key ring that's great for car keys or house keys. You can also attach it to your backpack. MULTI-USE - This emergency survival whistle is incredibly loud and very suitable for outdoor activities such as camping, fishing, hiking, pet training, boating, and so on. It's also perfect as a referee coaching whistle and rescue whistle. This whistle is a must-have in an emergency situation.