I've been researching rare earth magnets lately
and I bought a collection of them to experiment with.
I came across someone selling a magnet that
is meant to be placed on your oil filter.
The theory is that a filter cannot be made fine enough
to stop the really small metal particles, or the oil couldn't flow.
The magnet catches these particles as they pass through the filter.
What do you think?
Click to see the full signature.