Luban lock， originated in the ancient Han building's first tenon structure.This three-dimensional fight inserted convex portion of the interior of the appliance (ie tenon joint structure) engagement， very clever. Original wooden structure， the outside is a seamless cross cube. Ming lock more toys， shape and internal structure vary， generally easy to dismantle hard to install. When the assembly requires careful observation， careful thinking， analysis of its internal structure. It is conducive to the development of the brain， nimble fingers， it is a good educational toys.