The Luban Puzzle is also named as Interlock Puzzle. Based on the principle of the eight-diagram metaphysics, the concave and convex parts inside the three-dimensional interpolation toy, mesh perfectly. Luban Locks come in different shapes and sizes, with different internal structures. But they are usually easy to take apart but challenging to re-assemble. Each piece is approximately 3.5cm and weighs approximately 20g. This Luban IQ Puzzle is made from plastic and a great toy to keep bored kids on their toes as they challenge themselves to pull apart and put the pieces together again. Hours of entertainment fun! Buy from Play N Learn, a reputable and leading educational toy store in Singapore. Please take note, the price stated is for a single puzzle and we will ship out random designs.