I have not yet used the rubber stopper I ordered, but it is exactly what was described and exactly what I needed. I am restoring an old concrete fountain. The previous owner attempted to seal the hidden hole through which the wire for the small underwater electric pump passed and glue with pieces of the fountain together - without necessarily insuring that they were level - with clear caulking. Suffice it to say, he did not achieve either objective. He gave up and let the fountain fall into disuse. I ordered the stopper that I did because the hole was smaller than the wire that will pass through it and the taper of the stopper was just right. The wire is full a quarter inch in diameter. I will drill the stopper out to 3/16" and cut into with a hacksaw to enable me to insert the wire. I think that even with the slight loss of its diameter because of the sawing, it will work just fine with a forceful insertion into the hole for the electric wire. However, I intend to coat the outside of the stopper, the saw cut, and the wire passage hole with a thin coat of water proof adhesive so that movement of the fountain as I reassemble it will not cause the stopper to loosen. I will be sanding and man- handling the pieces of the pump to insure that they are level because I do not intend to use any kind of adhesive between concrete levels. I don't wish to leave the impression that I working on a copy of the Trevi Fountain. It is a simple three-level fountain. However, it is your product that will make it a working fountain and not just oddly shaped pieces of concrete scattered about.