puzzle is composed of twenty
four identical components, which assemble to form six squaress that
interlock with each other to form a hollow,
snug, spherical form. Assembly is not too hard.
Geometrically it is based on the "orderly tangle" of six squares first
described by Alan Holden. The idea to use lap joints and make a puzzle
from it comes from Teacher Lin and Sculptor Wu.
For background on its mathematical structure, see this paper.