A plug connector for use with a complementary receptacle connector, includes an insulative housing defining a receiving cavity therein and a plurality of passageways on opposite of the mating cavity, a pair of terminal modules stacked on each other and a metallic shell. Each terminal module includes an insulator and a plurality of contacts loaded on insulator, the contacts includes contacting sections extending out of the insulator and tail extending out of the insulator. The insulators of the stacked terminal modules are located behind the insulative housing and the contacting sections of the contacts are disposed in the corresponding passageways. The terminal modules and the insulative housing are commonly enclosed in the metallic shell.