A plug part which has at least one plug part housing having at least one elongate plug region for establishing a plug connection with another plug part in a plug-in direction, wherein the plug region has at least one electrical and/or optical plug contact for establishing at least an electrical and/or optical connection with the other plug part, and at least one step is arranged between the plug region and the rest of the plug part housing, wherein the plug part housing is of integral design and the plug region has an outer contour, wherein the outer contour, apart from the ends thereof which are at the end faces as seen in the plug-in direction, is designed to be free of recesses over the entire longitudinal extent thereof in the plug-in direction, or, with at least one recess.