Abstract: A film for tamper-proof coverings for product carriers consisting of platic is suggersted, which can replace the aluminum cover films known previously and which comprises a plastic matrix containing a particulate filler, this filler being selected and contained in the matrix with a proportion such that the penetration resistance of the film is reduced to below a limit of 450N/mm (measured on a film approximately 150 .mu.m thick).

Abstract: A guide sleeve for a rod or shaft movable parallel to the longitudinal axis in relative manner, comprising an outer ring and a guide ring of plastic inserted therein, wherein the outer ring and the guide ring are firmly attached to each other. The outer ring and the guide ring contact each other over a continuous contact surface, the outer ring being provided with grooves which are radially open towards the inside and have a cross-sectional constriction in the region of their mouth and the guide ring being provided with radially outward protruding projections which are received in the grooves.