A connector assembly (100) includes an insulative housing (10) defining a central slot (14) with two rows of passageways (16) by two sides thereof and two rows of contacts (20) disposed in the corresponding passageways, respectively. An electronic card (9) is received in the central slot and has a number of circuit pads (91) on a bottom portion thereof to engage the corresponding contacts, respective. Each of the contacts defines a contact section (22) extending into the central slot, and such contact section is of a downward bellows type with an overlapped region. The inner arm of the overlapped region provides a contact apex contacting the corresponding circuit pad. A height of the overlapped region is similar to a lengthwise dimension of the corresponding circuit pad.