Features: Make from metal alloy, this portable Whistles is light weight and builted to last. Small size and easy to carry. It can hungs on the necklace or keychains of the backpacks. Whether you're climbing mountain, camping in the wilderness, explorings new territory, or in need of Emergencies assistance, this Whistles will be your companion. Its louds sound can attract attention and help rescuers locate you quickly, ensuring your safety in critical situations. It can used in a variety of occasion, including camping, hiking, hunting, mountaineering and other outdoor sports activity. Also suitable for referees, lifeguards, dog training. Specifications: Component: metal alloy Size: about 5.1x0.7cm/2.01x0.28inch Package Includes: 1Pc Whistles note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.