An electrical connector including: an insulative housing and a plurality of contacts, the insulative housing defining a first mating face, a second mating face and a mounting face opposite to the mating faces, each contact includes a retaining portion for engaging on the insulative housing and a pair of contact portions exposed on the first mating face and the second mating face respectively, wherein the first mating face is higher than the second face in a direction perpendicular to the mating first and second faces.