As you can see, it has a chain with a catch one one side and then you squeeze the thingies that the chain is attached to and the other end opens.
My guess is that it’s a personal wine glass marker that you bring with you from party to party and attach to a necklace or something when you’re not using it. My mom and boyfriend don’t agree but they don’t offer a valid other suggestion.
I’ve seen similar thingies on necklaces, but they were just on plain chains. I was told that they were for when you don’t want a lot of necklaces, but you want to change your look. I’ve got a set of one pair of earrings with different gemstones that you swap out of the setting. Yeah, tacky, I know, but my mother bought it for me, what can I do?