An electrical connector includes an insulative housing defining a base portion, a mating port extending along a front-to-rear direction and a pair of guiding posts disposed at two opposite sides of the base portion, the mating port defining a front face perpendicular to the front-to-rear direction, the guiding post extending beyond the front face and defining upper and lower faces opposite in a vertical direction and an outer connecting face connecting the upper and lower faces. A plurality of conductive terminals are retained in the insulative housing and arrange in a longitudinal direction, and a shield shell enclosing the insulative housing. Each guiding slot defines a first guiding slot selectively disposed on at least one face of the upper and lower faces and the connecting face, and the first guiding slot is U-shaped and forwardly runs through a free end of the guiding post in the front-to-rear direction.