Abstract: A closure device for sealing a container includes a stopper and a cap assembly. The cap assembly is configured to surround both the stopper and a neck of the container in a sealed condition and includes a ring portion and a crown portion. The ring portion contains the stopper and includes a plurality of locking tabs. The crown includes a skirt telescopically mounted over the ring and configured to radially deflect the plurality of locking tabs inwardly under an annular collar of the container when the crown is axially displaced towards the neck of the container. A method of sealing containers using the closure device is also provided.