In the usual course of the door of the cupboard door, I am afraid that the most of the test is the hinge. It not only to Guiti and shutter accurately link up, but also shutter alone bear the weight and the cupboard door switching frequency up to tens of thousands of times must also be hold the door arranges consistency, otherwise after a period of time could rock with laughter. If there is a "perfect performance and flexibility of a body strong as iron", it is difficult to bear this responsibility.