"Pearl Vault" is a design of Dr. Bruce Patterson's who had the ingenious insight that the mechanism used by the planar "Magic Disk" puzzle could be applied to the faces of a regular polyhedron. He has kindly given me permission to sell the vertex version of his tetrahedral shell-puzzle which you see here.

The puzzle is about 2" long on its edges and consists of four congruent parts which all must move simultaneously to assemble or disassemble the puzzle. I.e., it is a coordinate motion puzzle. I made some small changes to the original design, including the creation of an internal compartment that holds a fake pearl.