Generation of Referring Expression with an Individual Imprint

A penetrator for penetrating a stopper sealing an opening in a container. The penetrator includes a stamped piece of sheet material formed to define a shank having a length. A groove extends along the length of the shank. The shank has a pointed distal. The stamped piece of sheet material further includes a bearing plate extending from the shank at a proximal end opposite the distal end of the shank.