The SRS invention comprises three pieces: 1) a spout, 2) a membrane and 3) a valve. When you start drinking you draw a vacuum under the membrane, which then pushed open the valve and you actually drink. After you stop drinking the membrane gets back into its original position and draws the valve close, that as a result prevents spillage of the fluid. The most important innovative feature of the SRS is that, on one hand, the closure opens instantly when being sucked on and on the other hand is closed at all times when not in use. When the suction stops the mechanism closes off the bottle automatically.