1. Inch scale, white paint scale, with the map can estimate the object distance.
2. Centimeter scale, inch scale, coordinate map can estimate object distance.
3. Sight scope, read the value through the scope, measure the azimuth angle.
4. Slope table for estimating distance.
5. Double-page chain, use more stable, increase the life of the compass.
6. Fluorescent effect means that the fluorescent dial can only appear after being absorbed into natural light, sunlight, light, ultraviolet rays, etc. The longer the continuous irradiation time is, the longer the luminous effect is, and there is no fluorescence effect without irradiation.
