You do have to double check to see if you put the clasp together properly,... the post can wiggle from side to side and completely miss the lock.  I have to be extra careful of what earrings I wear because the wrong earring can give me allergies... and I can usual tell within a few moments if the earrings are going to break my skin out.  *** But not with these sterling silver hoops.  If they didn't dangle, I would not know they were there.  I LOVE THESE earrings!