Used as compass for hiking, compass for camping, metal compass for hiking, compass with magnifying glass, emergency whistle with compassEmergency Survival WhistleBuilt-in whistle, flashlight, magnifying glass, sealed compartment, thermometer, mirror, compass, seven functions. Magnifying glass, in the case of no fire, can be focused. Mirrors can be revitalized using the principle of reflection.Compass, high accuracy, at a glance. Standard high decibel survival whistle. LED flashlight, no light premise, emergency lighting system. Thermometer to accurately grasp the current temperature. Survival information warehouse, can be opened, and the information is saved.Battery replacement method: the things apart, the middle part of the mirror to see inside, that is, behind the LED lights, there is a screw, that is, for the place of the battery button.7-in-1 Function: 1.Survival Whistle - Standard military regulations high-decibel to find out the whistle2.Compass - Refers to the North (South) needle (high accuracy, clear at a glance) 3.Thermometer - High precision thermometer (faster and more accurate the first time to grasp the current temperature)4.Reflection Mirror - Survival Reflectance Signal Mirror (using the principle of sun reflection to find the rescue of the staff to explain their current location) 5.Magnifying Glass-Help you to read small words or make fire in outdoor6.LED Light - High white LED flashlight (in the field without light under the premise of emergency use of the lighting system, LED light bulb life of 10,000 hours)7.Mini Storage Case- Sealed warehouse (in the trip before you can place their own lifeblood: write their own name, address, telephone, blood type, etc. in order to rescue your staff for the first time to master the situation)