My current job prevents me from getting my ears pierced, so I tried these for fun.  I bought these rather than a less expensive pair from another seller because one of the reviews on the other pair said they fell off.  I was worried these would, too.  The magnets were plenty strong enough, though.  After an hour or so, like clip-on earrings, they start to hurt from the pinching.  Also, and unfortunately, I've always had allergic reactions to certain metals against my skin.  I don't wear wrist watches, and I sew bits of cloth over the buttons on my jeans.  These start to make my ears itch after a couple of hours.  The stones are a little loose it the fittings, too.  For the price, that didn't surprise me, though.  These earrings answered my greatest concern, that they would fall off, by staying on tight enough to pinch with time, so they work the way I want them to.  I'm pleased enough.  The stones are 5mm in diameter,which makes them a bit on the large side