Multi-function Can Cap / packaging

Tightening the cap can prevent the dust from entering into the can. And when you can't drink a whole bottle,you can tighten the cap and take it away without spilling.Also,the bottom of the can can be covered with the cap so that you can put aside the can without falling when you finish one drink.With a concave shape, the bottom of the can can be stuck steadily so it will be easy for transporting and setting.