Durable material: these emergency whistles uses aluminum alloy and metal keychain, durable and non-toxic material, not easy to break, fade or corrode, double anodized treatment Loud whistles: aluminum alloy outdoor survival whistle can make big and bright sound, which can be heard from a long distance, very useful for various emergency situations; When outdoor travel, you can confirm the direction for you, avoid getting lost, find companions, etc. Matching key chain ring: each emergency whistle is equipped with a round key chain ring, compact and strong, elegant personality, can be hung on the key ring as an ornament, portable design, easy to carry around Dimension: length of these loud whistles is 4.7 cm/ 1.85 inches, diameter of the these whistles is 0.9 cm/ 0.35 inches, suitable size for your use and storage What you get: package includes 50 pieces of aluminum emergency whistle, don't worry about losing, enough for you to use in daily life, including 7 different colors, eye-catching and bright, easy to distinguish and find Product Description Read more