a 2-piece puzzle containing two identical pieces that, once assembled, form a tetrahedronAlthough this piece is bit different, credits need to go to Rinus Roelofs, who makes a lot of mathematical art objects with 3d printing. see www.rinusroelofs.nlI printed them with Cura 13.06.4 using the default setting "fast" with support, although support might not be necessary. Some slight cleanup/grinding was needed.Although it seems dead simple to assemble, it appears a challenge for most people that tried...