The part of a cosmetics unit is an applicator in the form of a brush (1). It is implemented as a sandwich injection-molded part consisting of two different plastic component s (9a, 11a). A first inner plastic component (11a) is injected by means of a single joint injection point (14) into a second outer plastic component (9a). The first inner plastic component (11a) and the second outer plastic component (9a) precisely rest against each other everywhere with regard to their contours. A connecting area is formed, so as to be free of gaps everywhere, between the first inner plastic component (11a) and the second outer plastic component (9a). The second outer plastic component (9a) completely encloses the first inner plastic component (11a), with the exception of the injection point (14). The sandwich injection-molded part (1) has a total weight of at most 10 g.