The problem is that the magnets on the back are very weak, so the jaws don’t stay in place as you are adjusting stuff against them. I didn’t realize just how weak the magnets were until one fell out the other day. I don’t know if it could hold up 5 pieces of paper to my fridge.
So, since it had fallen out anyway I instead hot-glued in some 1/4″ neodymium magnets. What a difference! I think it will work much better this way, and I could always add a few more power magnets if this isn’t strong enough.