Zero insertion force connector block

A zero insertion force connector block of the type having a body, two rows of contact terminals on opposite sides of the body, a pair of follower members between the rows of terminals with one follower member extending along each row of terminals and an interface between the follower members, and means securing the follower members to the body while permitting free movement of the follower members towards and away from the terminals wherein the improvement comprises an expansion element loosely confined in the interface for movement free of the body toward and away from the terminal rows, said element being movable between a first position where the follower members are free for movement towards each other to reduce the width of the interface and a second position where the element forces the follower members apart to increase the width of the interface, each follower member stresses terminals in one of the rows and the follower members and element float between the terminal rows, movement of said element between said positions controlling the movement of said terminals between open positions and closed positions wherein the terminals make electrical connections with adjacent contacts.