Abstract: A lyophilization stopper made of a rubber elastic material is composed of a shank (1) and a circular disc shaped flange (2) made in one piece with the shank. The shank includes a cavity (4) which surrounds the longitudinal axis (A) of the shank and is open toward the free end face (3) of the shank, while extending toward a central closed wall portion (2b) of the flange. A first section (Z.sub.1) of the shank disposed between a first transverse plane (Q.sub.1) and a second transverse plane (Q.sub.2) has a closed outer circumferential face which has a maximum diameter (D). A subsequent second section (Z.sub.2) includes a passage which communicates with the cavity as well as a plurality of projecting blocking elements (14a-14c). The inner wall surface (19) which laterally delimits the cavity (4) and has an increasing diameter with increasing approach to the free shank end face lies completely outside a cone (K) whose axis is the longitudinal axis (A) of the shank, whose tip (K.sub.

Abstract: The feeding nipple contains an annular connecting part the outer face of which defines a base plane and a central longitudinal axis perpendicular thereto, as well as a hemispherical shell and a hollow nozzle portion, integrally formed onto it via a narrowed neck part, having a suction opening in its rounded tip. All components form a one-piece hollow body of an elastomeric material which is mirror-symmetrical with respect to a plane of symmetry containing the longitudinal axis. A plane of division, perpendicular to the plane of symmetry and axially dividing the hollow nozzle portion in a longitudinal direction intersects the longitudinal axis near the base plane and is spaced apart from it at the apex of the rounded tip by approximately 6 mm.