Also, they have the most ridiculous -- ridiculous -- closing mechanism. Picture this: clear plastic shaped something like a thumbtack (i.e., flat disk with a stick coming out the bottom). At the end, there's a tiny, rubber ring that you just slip on the end. Teeny, tiny, and hard to hold. It's a miracle the thing didn't come off the end all day; I thought for sure I'd swallow it before lunch.
Let me just show you.
ETA: I think the problem may be that we bought a labret retainer instead of a tongue retainer. Duh. (In case any of you don't know, a labret piercing is through your lip-chin area. ... I don't know what to call that lip-chin area. Huh...)