The Magcom Tracer allows you to locate the rod end when concealed inside walls, conduit, flooring etc. This is particularly useful when locating obstructions.
Screw the Super Magnet onto a rod and feed it roughly into position. Sweep the area with the compass and the needle will reverse when it passes the magnet.

The Magcom Tracer is sensitive to approximately 60mm depending on the
material it has to sense through.