Lost some weight so decided to try this product rather that use the metal size reducers, that are a bit tricky to install properly.  The directions are good and the product easy to apply.  Actually, it was applied a little too thick, so I simply trimmed a little off with an exacto knife after it dried.  This seems to be the same silicone caulking product that you can buy in a hardware store in much larger quantities for relatively less money.  However, the smaller tube and nozzle allows for much easier application.  So far there have been no allergic reactions and the product wears well.  Also, the slight friction of the product contributes to keeping the ring from turning or slipping off.