Plug-in system comprising a plug (12a, 12b) and a plug-in module (14a, 14b), wherein the plug (12a, 12b) is designed to establish an electrical connection with the plug-in module (14a, 14b), the plug (12a, 12b) having: a plug member in which a plurality of electrical contacts are accommodated and which has a plug base that is designed to receive a collar of the plug-in module (14a, 14b); and a plug lever which is designed to be moved from an initial position to a final position and in so doing to pull the plug (12a, 12b) in the direction of the plug-in module (14a, 14b) by means of a lever arm that engages into the plug-in module (14a, 14b), wherein the plug lever can be fitted on the plug member in two orientations and, in both orientations, the lever arm and the plug-in module (14a, 14b) engage into one another in such a way that the plug (12a, 12b) can be pulled in the direction of the plug-in module (14a, 14b), wherein a plug-in channel of the collar is formed symmetrically with respect to the orientations of the plug lever, wherein the plug-in channel has, along a plug-in direction into the plug-in channel, a first section that provides two symmetrical projections, a second section that provides two symmetrical cutouts, and a third section that provides two further symmetrical projections, characterized in that the lever arm has a shaft about which the plug lever can be moved in an opening in the plug member, wherein the shaft is directed in the direction of the plug member, wherein the collar of the plug-in module (14a, 14b) has a plug-in channel which is designed to receive the shaft, and in that the shaft has a lever tooth which is designed to engage around one of the projections of the first section, wherein the lever tooth pulls the plug (12a, 12b) into the plug-in module (14a, 14b) as the plug lever moves from the initial position to the final position. a plug member in which a plurality of electrical contacts are accommodated and which has a plug base that is designed to receive a collar of the plug-in module (14a, 14b); and a plug lever which is designed to be moved from an initial position to a final position and in so doing to pull the plug (12a, 12b) in the direction of the plug-in module (14a, 14b) by means of a lever arm that engages into the plug-in module (14a, 14b), wherein the plug lever can be fitted on the plug member in two orientations and, in both orientations, the lever arm and the plug-in module (14a, 14b) engage into one another in such a way that the plug (12a, 12b) can be pulled in the direction of the plug-in module (14a, 14b), wherein a plug-in channel of the collar is formed symmetrically with respect to the orientations of the plug lever, wherein the plug-in channel has, along a plug-in direction into the plug-in channel, a first section that provides two symmetrical projections, a second section that provides two symmetrical cutouts, and a third section that provides two further symmetrical projections, characterized in that the lever arm has a shaft about which the plug lever can be moved in an opening in the plug member, wherein the shaft is directed in the direction of the plug member, wherein the collar of the plug-in module (14a, 14b) has a plug-in channel which is designed to receive the shaft, and in that the shaft has a lever tooth which is designed to engage around one of the projections of the first section, wherein the lever tooth pulls the plug (12a, 12b) into the plug-in module (14a, 14b) as the plug lever moves from the initial position to the final position.