A hinge is mounted between a cover and a base of an electronic device and has a first actuating unit, a pivoting limit and a second actuating unit. The first actuating unit has two tops. The pivoting limit is mounted pivotally between the stops. The second actuating unit selectively abuts a first side and a second side of the pivoting limit. When the second actuating unit abuts one of the sides of the pivoting limit to pivot the pivoting limit, one of the sides of the pivoting limit abuts one of the stops to limit the rotating angle. With the pivot of the pivoting limit, the rotating angle is increased. Therefore, the cover of the electronic device is fully rotatable by 180 degrees in either direction, and the hinge still provides limiting function to protect inner wires.