Lu Ban locking puzzles are based on the mortise and tenon joinery of traditional Chinese architecture. These ingenious constructions use shaped concave and convex pieces (i.e. mortise and tenon) that lock tightly to create joints without using a single nail. On the outside, they look like tightly fitted cubes, but there is always a knack for disassembling them. These puzzles are conducive to brain development and manual dexterity, making them powerful educational toys. http://en.people.cn/n3/202

An experiment on locking and unlocking🧐😱 | ITS JP