Apparently, it doesn't like glass surfaces because it keeps falling off even though I've added extra adhesive strips & let it "sit" for > 24 hours before putting anything on it.

I really like the writing surface but the magnet was weak and the board fell off frequently

The surface can easily be scratched simply by moving a magnetic around on it

Pros:I love the magnetic writing surface

One upgrade I would consider is provided better quality double sided foam tape that does not damage surfaces (like the 3M stuff on towel hooks, that you can pull the elastic-foamy tab and it easily detaches to surfaces