This emergency whistle features a double tube design with a larger caliber and louder whistle, capable of producing high-frequency sounds. This lightweight emergency whistle comes with a keychain, making it easy to carry and not easily lost. The whistle is made of aluminum alloy material and is colored using anodizing technology, which is not easy to fade and has a longer service life. Whistles can be used in mountaineering teams to confirm the position of team members and ensure their safety. You can also hang it on your child's backpack and whistle when they feel danger, attracting the attention of pedestrians and asking for help. This whistle is also suitable for deaf and mute people. It is Ideal for hiking, camping, fishing, boating and hunting,etc.