Quadro

Quadro. This little box is a packing problem puzzle in which you must fit 6 square blocks into the box.  To complicate the task, there is an acrylic top with a square hole just big enough to fit a piece through.  After putting a few  pieces in, it soon becomes apparent that the blocks inside are getting in the way, and it becomes difficult to figure out how to get the last pieces in. There is- Quadro.