The Vacuum Straw is like any other regular plastic straw except for one exception. It has a oval shaped device 3/4ths of the way up the straw. Inside the device is a small pump between the two ends of the straw. The pump is powered by a watch battery. On the outside of the device is a small button that when pressed causes the pump to turn on and bring liquid up the straw and expel the liquid out of the top of the straw.
Purpose
Two purposes that come to mind are as a novalty item and an aid for elderly or disabled users.
