A cable assembly (100) includes an insulative housing (2) having a base portion (21) and a tongue portion (22) extending forwardly therefrom, at least a mounting cavity (2212) and a curved slot (2213) defined in a low section of the insulated housing, said curved slot located behind and communicated to the mounting cavity; a plurality of contacts (4) supported by the base portion, each contact having a mating portion arranged proximate to the top side of the tongue portion, and a tail portion extending beyond a back surface of the base portion; an optical module (6) accommodated in the mounting cavity and a spring member (63) arranged between the optical module and a back side of the mounting cavity; an optical fiber (53) extending through the curved slot and connected to the optical module; and a metal shell (8) having a mating frame enclosing the tongue portion and the optical module therein.