An electrical connector includes an insulative housing and a terminal retained in the insulative housing. The insulative housing defines a mating surface and a mounting surface opposite to the mating surface, a pair of first side faces connecting with the mating face and the mounting face. A receiving room penetrates through the pair of first side faces and a through hole runs through the mating face and communicates with the receiving room. The terminal includes a mating board of frame shape received in the receiving room and soldering legs bending from the mating board to expose to the mounting face. The mating board has an open therein. Two spiral mating arms extend oppositely from opposite inside edges of the opening of the mating board with free ends thereof aligned with the through hole.