"1. Thermometer: Measure the ambient temperature. (-20-60°C)
2. Hygrometer: Measure the relative humidity of the environment.
3. LED lights: Convenient for use at night. Replace the battery:
(1) remove the magnifying glass and ruler (2) loosen the three screws (3) replace the battery
4. Reflector: Reflector to ask for help in the countryside, reflect the sun, and send a light signal.
5. Spirit level: determine the level condition
6. Compass: Magnetic azimuth measurement (the relative function of the compass to acquire data at horizontal and vertical levels.)
7. Whistles: ask for help in the countryside, send a signal, (Use the tappet to push the whistles from the third hole on the left)
8. Magnifier: Find a coordinate on the map.
9. Ruler: Measurement distance."