Abstract: An insulation piercing connector (2) is held inside a base body (1), and a closing element (3) is guided inside said base body. The closing element can be transferred into a closed position at least from one open position, in which a conductor (4) can be inserted into the closing element (3). By transferring the closing element (3) into the closed position, the conductor (4)can be inserted into the insulation piercing connector (2) and can be held and clamped therein. An over spring (7) is arranged on the closing element (3). Said over spring surrounds the insulation piercing connector (2) and contacts the same via contact pieces (8) whereby exerting a pressure force (F) onto the insulation piercing connector (2).