The design of universal receptacle holes of the series product of receptacle is compatible to various plugs of international standards used in the United States, Asian, European and African countries. The design of universal functions makes possible various ways of assembly of receptacle according to desires. Wonpro products are easy to be assembled and replaced. With the design of a retaining slot and wire-withdraw press and accurate positioning device, the current leads are easy to be plugged in or out according to your desire. The flexible and elastic metal pieces contact the plug closely and the closeness of contact remains even after 10 thousand plugs in and out. The additional protection shutter is a unique design in China for double guarantee, Power is not supplied unless the two protection shutter are opened simultaneously and this mechanism prevents wrong plug-in in one hole and protect children from electric shock.