The plurality of the terminal grooves 124 are arranged in two rows along an up-down direction perpendicular to both the longitudinal direction and the transverse direction. The insulating housing 10 has two opposite docking surfaces 101. A top surface and a bottom surface of the docking portion 120 are defined as the two opposite docking surfaces 101. The two rows of the plurality of the terminal grooves 124 extend and penetrate through the rear surface of the tongue portion 12 along the longitudinal direction, and penetrate through the fronts of the two opposite docking surfaces 101 along the vertical direction. The terminal grooves 124 are transversely arranged in each row. The two rows of the plurality of the terminal grooves 124 penetrating through an upper portion and a lower portion of a rear surface of the limiting portion 121, and an upper portion and a lower portion of the first docking portion 122 along the longitudinal direction, and a top surface and a bottom surface of the second docking portion 123 along the up-down direction.