The present invention concerns a wedge for a lead-through system. The wedge comprises a first wedge element, a second wedge element, a third wedge element and a fourth wedge element. The first and second wedge elements are arranged moveable towards and away from each other. The third and fourth wedge elements are placed on opposite sides of the first and second wedge elements, abutting the first and second wedge elements along sloping surfaces. The wedge elements and the sloping surfaces are so arranged that the third and fourth wedge elements will be moved away from each other when the first and second wedge elements are moved toward each other and that the third and fourth wedge elements are moved toward each other when the first and second wedge elements are moved away from each other. The wedge further comprises a bracket on the outside of the first wedge element. The bracket receives a socket arranged to be able to rotate in relation to the bracket. A compression screw is connected with one end to the second wedge element and goes through an opening of the first wedge element. A head of the compression screw is received inside the socket of the bracket.