An electrical connector includes a frame including at least two supporting arms configuring at least one mounting area, at least one housing unit assembled to the supporting arms and located with the at least one mounting area. An inter-aligning arrangement is arranged between the supporting arms and the at least one housing so as to ensure the at least one housing unit is properly attached to the frame. The inter-aligning arrangement includes at least one groove located at one of the supporting arm and the housing unit, and at least one projection located at the other.