This small bottle with a cork charm is really unusual. It can be used to hold any tiny momento or treasure. It has a loop on top so that you can where it on a chain. I would recommend gluing the cork in the bottle though once you have your treasure in it so that it does not come loose if you where it on a chain. You could put sand from your favorite beach, very tiny shells, a tiny love note,  and many many other things that you might think of. The metal loop on top is not sterling, but a silver base metal. This round bubble bottle is 36 mm long with the loop and 17 mm in diameter at the bubble. The opening is about 5 mm. Look for the other shape in my store that is more cylindrical.