When a clipping member is fitted onto the outer peripheral surface of a sealing member, the tightening margin for elastic fitting is provided to the sealing member by the fastening force of the clipping member. In this case, the clipping member includes an opening portion formed to have a partial separation in the circumferential direction and is formed from a metallic material approximately in a C shape having an inner diameter smaller than the outer diameter of the sealing member. Also in the case where a permanent set occurs in the rubber elastic body (the sealing member) as time passes, the clipping member is reduced in diameter by the elastic restoring force of itself. Accordingly, the tightening margin for elastic fitting to the stabilizer bar can be continuously provided to the sealing member.