An Expansible Plunger; An Attachment Unit And A Method For Attaching A Container Element In A Container Body

An expansible press plunger, the expansible press plunger extending in an axial direction and in a radial direction perpendicular to the axial direction, the expansible press plunger being expansible in the radial direction and comprising a base plate and a first plunger skirt, the base plate having a bottom surface with a circumferential edge defining a shape of the bottom surface, the base plate having a guiding surface opposite the bottom surface, the first plunger skirt having a top end and a bottom end and a circumferential edge portion at the bottom end of the first plunger skirt, the circumferential edge portion of the first plunger skirt being arranged at the guiding surface of the base plate, the first plunger skirt being resiliently transformable between an unexpanded state and a radially expanded state, wherein,

• the expansible press plunger comprises a second plunger skirt, the second plunger skirt having a top end and a bottom end and comprising a plunger skirt side wall having an inner surface and an outer surface, the plunger skirt side wall extending from the top end to the bottom end of the second plunger skirt, the plunger skirt side wall comprising a circumferential edge portion at the bottom end of the second plunger skirt, the circumferential edge portion of the second plunger skirt being arranged radially outward of the circumferential edge portion of the first plunger skirt, the second plunger skirt being resiliently transformable between an unexpanded state and a radially expanded state.