Durable Material:These outdoor survival whistles are made of a hard alloy, decorated with more colors of rhinestones, and feature a metal chain and ring. It is durable, lightweight, and easy to carry. To ensure a loud, clear sound, blow the whistle firmly and continuouslyRelevant Usage: A whistle for coaches is a lightweight survival tool. A sports whistle is suitable for various outdoor activities such as outdoor travel, hiking and fishing, making them important tools for attract attention during outdoor travel and emergencies. Feature: This metal whistle features a unique dual-chamber design. A strong blow produces a loud and clear sound. The water rhinestones embedded in the surface provide excellent reflective properties outdoors, facilitating quick location in emergencies.