The cans are just made for containing the liquid until it is drinked, then they get out of date but with this idea we solve that and another problem that cans have.
With this system we can close the can whenever we want so we don´t need to drink it completely, if we dont want more we can close it and put it in the fridge without loosing quality (gas, flavor, etc...).
Also when we finish the can, we can clean it and use it again with other liquids, we can refill it as many times as we want with the sensation of having a new one each time.
With the rotative system is very easy and very cheep, just adding a new layer that close it again. This rotative layer can be also used as publicity for the brand.