Mold-release agent for producing thermoset moldings with a hydrophobicized surface, where the agent comproses at least one compound with mold-release action, and also at least one reactive, where appropriate hydrolyzable, silane compound, which is capable of reacting chemically in situ with the thermoset surface which forms during the molding process. The device has a first electrode and a second electrode, with an organic semiconductor layer disposed between the first and second electrodes. The sub-medium region includes a plurality of inner sub-medium regions arranged along the outer circumference of the core region and a plurality of outer sub-medium regions arranged on outer of the inner sub-medium regions. Thus, fuel pressure pulsations and shock waves are reduced by bending the absorbing surface, and emission of high-frequency noise is eliminated. In the operative position, the foot bar is positioned for desired use in pre-determined exercises while in the storage position it is positioned so as to permit nestable stacking of a plurality of the chairs.