Rubber stoppers can be used for a variety of uses in fountains. But generally are used to plug the hole into the basin holding the pumps. This method results in a hidden cord. These stoppers will accept smaller and larger corded pumps (if the center hole is drilled out). The sides can also be easily split if your application requires it. Use a small bead of silicone around the edge to completely seal the hole. The stopper is easy to remove for pump servicing or replacement.