Container of thermoplastic material

A plastic hollow body comprising:

• the hollow body in a form of a fluid container configured to contain a fluid;
• at least one built-in fitment component or attachment disposed within an interior of the hollow body and joined to a wall of the hollow body, wherein the wall has an inner side facing the interior of the hollow body and an outer side facing opposite the inner side;
• wherein the hollow body and the built-in fitment component or attachment are positively lockingly joined together;
• wherein the built-in fitment component or attachment includes a foot element having a stepped configuration towards the wall of the hollow body which forms a stepped contact surface which contacts the wall of the hollow body;
• wherein the foot element includes at least one through opening having a longitudinal length extending through the foot element along a longitudinal axis and a through opening dimension transverse to the longitudinal axis;
• and
• wherein plastic material of the wall of the hollow body occupies the at least one through opening and forms a head having a head dimension transverse to the longitudinal axis which is larger than the through opening dimension of the at least one through opening which engages with the foot element such that the built-in fitment component or attachment is positively lockingly joined to the wall of the hollow body, wherein the plastic material of the wall of the hollow body which occupies the at least one through opening and forms the head has a solid cross-sectional thickness whereby the head is not hollow.