A card edge connector includes an elongated housing, the housing extends along a longwise direction thereof and has a pair of opposed side walls, a central slot between the side walls, and a tower portion disposed at one end thereof. A plurality of contacts are retained in the housing. An ejector mechanism is rotatable retained in the housing and has a body portion, a flexible arm divided from the body portion and a locking protrusion located on the flexible arm. The lock protrusion is adapted to resist the tower portion during the ejector mechanism rotates with respect to the housing.