Abstract: An electrical connector (1) includes an insulative housing (10) having a first end (14) having a supporting section (13), a second opposite end (16) including a lever (17), and a slot (18) extending from the first end to the second end, and a number of electrical terminals (12) mounted to the insulative housing. A memory module (2) has a first side portion (20) including a side engaging section (26), an opposite second side portion (22) including a locking section (28) and a number of conductive pads (21). When the memory module is to mate with the electrical connector, the side engaging section engages with the supporting section and the memory module is rotated on the supporting section to mate the conductive pads with the electrical terminals sequentially from the first end to the second end. The lever locks with the locking section to hold the memory module in the slot.