There's room for small items, but be careful with the narrow opening, as it can be hard to retrieve items out of the cache. Also, ensure container remains firmly attached to the wire to keep it from disappearing during flooding.
My son was on a kick to place a cache, and when he finished with his vitamins, he asked if we could turn his empty bottle into a cache container. No problem! Thus, this one has the name "Vitamin G" - the G for geocaching! This spot is near a main trail, so be careful of muggles when retrieving this one.