These micro ocarinas are made by a craftsman called John Langley, well known for making English pendant style Ocarinas. He claims this is the world's smallest playable wind instrument and I believe him.
It can sound very nice when played well, but I don't dare play it within earshot, because it can be rather shrill in the wrong hands. But what better reason to become a mountain dwelling hermit?
Click here to see the rear of the Ocarina with the maker's signature.