An electrical connector includes a plurality of contacts and an insulative housing. Each contact comprises a retaining portion, a contact portion contact portion and a tail portion, the contacts divided into a first group and a second group. The insulative housing defines a mating face and opposite first and second side faces. The insulative housing defines two rows of mating passageways extending in a first direction running through the mating face. The tail portions of the first group expose to the first side face and the contact portion contact portions of the first group project in one row of said two rows of the mating passageways. The tail portions of the second group expose to the second side face and the contact portion contact portions of the second group project in the other row of said two rows of the mating passageways.