A hybrid plug connector including an insulative housing defining a cavity to receive an optical fiber assembly therein, and a plurality of passageways to receive a plurality of terminals therein. A printed circuit board is located behind the terminals and connected to the terminals. An electrical cable is mounted to a rear portion of the circuit board. The whole optical fiber assembly is received within the housing and is somewhat back and forth moveable along a front-to-back direction for buffering for compliantly coupling with another optical fiber assembly built within the complementary receptacle connector when the plug connector is inserted into the complementary receptacle connector. A lens module is formed on the optical fiber assembly for collimating the light beams from the optical fibers.