Abstract: A closure for use with can-type containers, having an opening formed in one end by removing a portion of the container material. The closure has a vertical sidewall, forming a chamber within which a hermetically sealed elastic membrane is fastened, and an actuator plate resting within the vertical walls on the upper surface of the hermetically sealed membrane so that by downward movement of the actuator plate the membrane is forced to expand within the container opening, and with further downward movement of the actuator plate expands inside the container to provide a seal.