The Diagonal Burr is a classic that has been around for a long time. The Pseudo-Notched Sticks puzzle has the external appearance of a Diagonal Burr, however the pieces are not what one would expect. if you grab the ends of what appears to be a solid stick, you are only holding the puzzle more tightly together. if instead you grab hold onto one end in each hand and pull the stick apart, you discover the clever dissection. essentially, the pieces are turned 90 degrees from what you would expect. assembly is somewhat tricky because the strange shape of the pieces makes it difficult to get a good grasp on the two halves.

I've always made these puzzles as matched sets where the pieces can be interchanged in order to make hybrid solution shapes.