The Wine Saver Concerto is a vacuum pump, which extracts the air from an opened bottle and reseals 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 from within the pump 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 on a later date.