Abstract: An air spring (2) essentially includes two end elements (4, 6) and an electrically conductive rolling-lobe flexible member which is pressure-tightly arranged therebetween and is made of a flexible elastomeric electroconductive material (14). A reinforcement (16) formed by two cord fiber plies (16a, 16b), which are made of fibers (18), are vulcanized into the flexible member. In order to determine the height (h) of the spring, preferably, the two cord fabric plies (16a, 16b) are provided with a number of highly conductive fibers (18a) which are arranged at the beginning and the end of each ply in a parallel direction to each other, thereby forming two conductive strips (24a, 24b). The conductive strips (24a, 24b) are disposed oppositely to each other and are electrically connected at the end of the rolling-lobe flexible member (8) in such a way that a conductive loop (24) is formed and each strip is used as an element in a branch for an alternating-current measuring bridge (28).