Fake Screw small (DM11x25)

Here is another container like a small "screw".
But its a fake to hide something inside (like a geocache logbook).
On the nut side is a cut out, to place a magnet Dm 3mmx3mm with clue.
If the magnet is placed you can put the screw on steel metal things.
Uninitiated persons only see a screw.