[Dimensions] The whistle is 7cm long, the clip is 2cm wide, and weighs about 8g [Material] PP [Use] For women's self-defense, outdoor team communication, self-rescue in case of disaster, self-rescue in earthquake, fire, or flood. Total weight: 14 grams 1. Dual-frequency design.The differently sized sound chambers on the left and right sides simultaneously produce high and low-frequency sounds, providing penetrating power in various environments and conditions. 2. Anti-detachment design of the whistle tip.You can hold it in your mouth without using your hands, and you don't have to worry about the airflow blowing the whistle out. 3. Vocalization is effortless.When seeking survival or help, be careful to conserve your energy; a good survival whistle can easily produce sound.Some products on the market may have a loud sound, but it is not easy to produce a sound. 4. Integrated design, sturdy and reliable.