This is a box that has 4 locking plugs. No matter what direction you tilt the box in, at least one plug will lock the lid in place. The only way to open the box (without destroying it) is to spin it around quickly, forcing all 4 pins out to the side.
This is a cufflink Lego minifig upper body. If you add legs, arms and a head to it, then you have a complete Lego minifig cufflink. The best material is probably the Cream Robust, which is ABS, the same material as Lego bricks.