The Wine Saver is a vacuum pump, which extracts the air from the opened bottle and re-seals it with a reusable rubber stopper. Place the reusable stopper in the bottle and extract the air from the bottle using the Wine Saver pump. A "click" sound tells you when you have reached the optimum vacuum level. The vacuum slows down the oxidation process which makes it possible to enjoy your wine again at a later date. The question "how often do I have to pump?" is a thing of the past. The unique and patented vacuum indicator will emit a "click" sound when the correct vacuum is reached. *Not for sparkling wines- Includes one patented cork.