Features: Make from Metal, 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 reliable companions. 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: Materials: Metal Type: Sandblasting with Small Rings/Sandblasting with Small Rings and Rope/Sandblasting with Small Rings and Chain/Sandblasting with 23mm Metal Rings Size: About 5.30x0.8cm/2.09x0.31inch Package Includes: 1Pc Whistles with Small Rings/1Pc Whistles with Small Rings and Rope/1Pc Whistles with Small Rings and Chain/1Pc Whistles with 23mm Metal Rings note: Please allow 1-2cm errors due to manual measurement, make surely that you not mind before order. Due to difference between different monitors, the picture may not reflect the actual color.