[Name]: Large Camping Rescue Whistle [Color]: army green. [Package]: Simple Packing White Box [Weight]: 50g [length]: 9.8cm [diameter]: 3cm Special note: If you unfortunately find yourself in an earthquake-prone area, or if you or a friend are engaged in hazardous work, prepare for one as soon as possible. Little things make a big difference at times critical times. The Wenchuan earthquake, the recent Yushu earthquake, and the flood accident at Wangjialing Coal Mine are all lessons learned. High quality ABS material, loud sound, foreign trade quality [Function] This whistle is multifunctional in one: whistle, compass, thermometer, magnifying glass, reflector, LED light and other functions. [Features]: The whistle is army green, lightweight and practical, cylindrical design, especially suitable for field use. In nature, the whistle not only has the function of picking up whistles, but also to save lives Multifunctional in one: whistle, compass, thermometer, magnifying glass, reflector, LED light, small storage compartment. Originally equipped with a lanyard, it is very practical to hang around the neck during field activities It is an adventure, travel and leisure camping product. Features: 1. Standard High Decibel Survival Whistle (The patented sound inner compartment makes the whistle farther and harder) 2. North (South) Needle (Very precise and clear at a glance) 3. High thermometer (Faster and more accurate time to enter current temperature) 4. Survival reflective signal mirror (The person who uses the principle of sunlight reflection for search and rescue will explain their current position) 5. Tinder magnifying glass (In the absence of fire in nature, the principle of focusing sunlight on a magnifying glass can be used to refract sunlight on grass and withered leaves to generate fire, which is better than "drilling wood for make fire" ~~ Ha ha ~ ~) 6. White High Light LED Flashlight (Assuming that there is no light in nature, the life of the lighting system and LED bulbs for emergency use is 10,000 hours) 7. Sealed warehouse (You can put your own lifeguard on it before going out: write down your name, address, phone number, blood type, etc. so that lifeguards can track your situation) 8. Nylon lanyard (It's more convenient to carry) [Battery replacement method] Take the thing apart, look inside the mirror part in the middle, it's behind the LED light, there's a screw, that's the place to change the button battery.