Product Name: Outdoor Survival Whistle Material: Aluminum alloy, double-layer anodized treatment, not easy to fade 9 colors: red, green, blue, silver, black, purple, gold, rose red, sky blue The specifications include a length of 47mm without the ring and a diameter of 9mm, and can be laser-etched with a logo Features double-layer anodized treatment, making it resistant to fading; compact and sturdy, it can assist you in determining your location, avoiding getting lost, finding companions, and other tasks during outdoor travel; can be hung on a keychain as a decoration; elegant and unique, the whistle produces a sharp and loud sound; it is a professional outdoor survival whistle made of aluminum alloy, with a characteristic loud sound