IF ALL THE INNER PIECES MET IT WOULD HAVE BEEN A REGULAR TUMBLING BLOCK. iT STILL IS EXCEPT YOU OUTLINED THE MATERIAL IN THE MIDDLE. tHATS VERY PRETTY. iT ISN'T LIKE THE HOLLOW BLOCKS I HAVE SEEN. I THINK THIS ONE ABOVE IS EASIER TO MAKE. DID A QUILT OF TUMBLING BLOCKS FOR A CHILD. NOW THAT I SEE YOURS MAY DO ANOTHER.