Discovered this on the inside of a 3d-printed puzzle tube at the Lazy Days event this year. Slacking off a bit with regard to logging this, but it's better late than never!
Very cool container to house the trackable tag! I saw something online that reminded me of your container. Someone near Amsterdam made one out of aluminum, and is using it as a cache container! The picture showed that it's been in the field for a while, and hasn't been stolen. I wish more people around here would be more respectful of geocaches so we could have more cool containers like that around the U.S. instead of being inundated by bison tubes & altoid tins.
Happy Caching!