I have a metal mailbox without a flag. The only way to send mail without having to go to the post office is to clip it to the mailbox. I have tried many different clips and magnets. They all fall off the first time the mailman grabs soemthing from them EXCEPT these. YEAH!
I used to hold up a sign I made for a farmers market (not your conventional use) ! It needed to do the job and look good. It did both. It also held a cloth back for me at the same time. Basically it was almost perfect...1 thing...just a bit too heavy but still did the job.
What can I say these clips do the trick. They have a good strong magnet and the clip hinge is pretty tough too. I can put up plenty of pages no problem.