teambuckle 10 in 1 Multifunction Outdoor Survival Military Camping Hiking Compass Tool Kit Compass: Measure for magnetic azimuth (Relative functions of compass: acquire data at horizontal and vertical level). Thermometer: Measure for ambient temperature. Hygrometer: Measure for ambient relative humidity. LED light: Lighting. Reflector: Call for help in country-side, reflect sunlight to sent out the light signal. Spirit level: Determine level condition.