Flask with about a holding member Ratcheting piston rod

Holding elements that prevent the piston rod from being drawn out of the piston are secured in the piston opening. The object of the invention is to provide a reliable and easy-to-mount attachment of the piston rod in the piston (2) which is also capable of absorbing the considerable tensile forces exerted between piston rod (21) and piston (2). A holding element (5) preferably made of plastic is first mounted on the piston rod (21) and the unit thus obtained is snapped into the piston (2).