While comprising filled minor compartments being filled with an inclusion in which a liquid makes the major component, and vacant minor compartments being filled with the air, at least one of the vacant minor compartments adjoins the filled minor compartments, and a fragile section is formed in at least one of ribs that demarcate the filled minor compartments and the adjoining vacant minor compartments. After the fragile section has fractured, shock energy can be absorbed furthermore by means of circulation resistance to the inclusion that flows from the filled minor compartments to the vacant minor compartments.