An attachment system, which is to be introduced in a mounting opening (5) of a hollow body (3), includes a rear engagement member (4) for engaging from behind holding projection (17.1, 17.2) of the hollow body (3), at least one stop (6, 37) for engaging edges of outer sides of the hollow body which limit the mounting opening (5) and connected with the rear engagement member (4) by a screw, and a device providing for a relative rotational movement between the stop (6) and the rear engagement member (4) about an axis of the fastening means (7; 35) and formed as a transformation device (9; 31) for converting a translational movement of the screw (7; 35) relative to the stop (6) in a rotational movement of the rear engagement member (4) relative to the stop.