PREMIUM MATERIAL- This emergency whistle is made of high-grade aluminum alloy, waterproof, sturdy and durable. The surface is anodized and does not fade. Its surface is smooth and not easy to stick dust. It can be used for a long time. DOUBLE TUBES DESIGN- Double-tube design provides a louder and crisper sound. It can be heard from a far distance without any effort to blow. Excellent airflow design allows being used in all weather environments, nothing to jam. It allows you to be well noticed in an emergency situation. HIGH DECIBEL- This double tube emergency survival whistle can provide you with up to 120 decibels of sound. It is fantastically loud and crisp sound. It can be heard for far distances which can be perfectly used as a signal whistle or a rescue whistle. LIGHTWEIGHT & PORTABLE- The emergency survival whistle is only 10g, and the dimension is 5.7*1.5*0.8 CM. Lightweight and convenient to carry out. It comes with a key ring which is a good way to use with car keys or house keys. You also can tie it to your backpack. MULTI USE- This emergency survival whistle is fantastic loud and very suitable for outdoor activities like camping, fishing, hiking, pet training, boating, and so on. It is also perfectly used as a referee coaches whistle and rescue whistle. It is necessary to have this whistle in an emergency situation.