Invented by Napa Valley Winemakers, CapaBunga is made of silicone - the same material used to make bungs for barrel aged wine. Each pack contains two CapaBungas in bright colors with fun sayings and drawings. The air and liquid tight seal allows you to lay the bottle on its side in a refrigerator without leaking. And since the cork (or lesser wine stoppers) do not stick out of the bottle, the wine will easily fit into the door of the refrigerator. CapaBunga is so easy to use that you will never try to shove a cork back into a bottle again.