They work pretty well. I had a case back which I will never see again but these earrings have a very thin shank. As long as you check them several times a day, you should be fine. I play with my earrings all the time so I usually make sure the backs are still tight. I'd rather lose one of the backs than an earring. They are cheap and work quite well. I will buy them again if I ever run out of the 100 I just bought!
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