I recently purchased some of the new Geomag Kids pieces, and was fooling around with them. One thing I found is that the large holes in the Geomag Kids panels can allow for some interesting combinations of constructions. This one illustrates the mathematical idea that the dual of the cube is the octahedron. I found that an octahedron made from (classic) Geomag Pro rods (scale 2) would just poke through the openings in the large panels of a cube made from Geomag Kids rods.