In the present embodiment, the wire covers and the wire leading-out holes into which the wire covers are press-fitted are formed so that the contour shapes of the horizontal cross-sections of each of the head parts 801 of the wire covers and the first hole sections 701 of the wire leading-out holes have two-fold symmetry with respect to the respective center axis. Specifically, the wire covers and the wire leading-out holes into which the wire covers are press-fitted are formed so that when the wire covers 8b, 8c and the wire leading-out holes 7b, 7c are caused to rotate about the respective center axis, at least the contour shape of the horizontal cross-section of the head parts 801 of the wire covers and the contour shape of the horizontal cross-section of the first hole sections 701 of the wire leading-out holes have rotational symmetry so as to overlap an original shape with each rotation of (360/2) degrees.

In order for force to be applied in a substantially equal manner to each part of the wire covers when the swaged parts 9 of the end member 201 that are established at the peripheral edge of the openings in the wire leading-out holes are swaged after the crush ribs 804 have been crushed and the wire covers have been press-fitted into the corresponding wire leading-out holes, it is desirable for rotational symmetry to be imparted additionally to an array of the swaged parts 9, of which a plurality are established, and to an array of the plurality of recesses 805 provided to the head parts of the wire covers.