These backs work well to keep the earrings on - I used them for some hoop earrings I have. They fit ok so that my earrings stayed on. However, they are not hypoallergenic, the plastic part is of course, but the metal is not. They caused a reaction in the middle where the skin touches the metal. So just a warning if you have sensitive skin and/or are allergic to nickel, I would pass on these. If you have no problem with sensitivities, these will work ok.