Description High Quality Materials: This Emergency Whistle Is Made of High Quality Aluminum To Ensure Durability and Safety. It Uses High-Frequency Dual-Chamber Resonance, and The Volume Can Reach 150Db, and The Sound Can Easily Travel Far. The Whistle Has A Smooth Surface and Is More Practical and Structured Than Other Materials. . Advantages of The Emergency Whistle: This Emergency Whistle Has Excellent Airflow Design, The Surface Is Anodized for Color Formation, Will Not Fade and Has Longer Service Life. and It Has No Moving Parts, No Soundproof Parts, Waterproof, Can Be Used All Day Weather, Rainy Days, Wet Weather. . Widely Used: This Emergency Whistle Can Be Used for Camping, Hiking, Hunting, Fishing, Boating, Cycling and All Kinds of Outdoor Activities. In Addition, It Can Also Be Used As A Referee Whistle, A Dog Whistle, A Security GuardS Warning Whistle, and A Safety Whistle for A Person Going Out Alone, Especially for A Girl Going Out Alone. . Practical and Stylish: Each Emergency Whistle Has A Keychain That Easily Attaches To A Backpack or Belt, or Can Be Worn Around The Neck With A Rope So You Can Whistle Quickly. The Appearance Is Simple and Generous, Convenient and Practical, and Has A High Safety Factor. Carrying A Gold Whistle and A Silver Whistle Is Also A Nice Asset