Magnetic Field Viewer
Position the viewing film (green area) on top of any magnet to discover where it's magnetic poles are located and how many it has.
The area between the poles is indicated by a light green "aura", while the poles themselves appear dark green.

How it Works
Encased in this green film are millions of magnetic particles  suspended in oil. The magnet attracts these tiny particles to the area where the magnet is the strongest, at the poles. The image created is identical to the magnetic field of the magnet.