A plug connector has a cylindrical housing body having at least one step, which forms two different regions each having different housing diameters, wherein the region having the smaller diameter forms a plug-in region and the region having the larger diameter forms a socket region, wherein the plug connector has a lock, which is captively connected to the housing body, wherein the plug connector has an actuator, which is operatively connected to the lock, wherein the plug connector has a plugging positioner, which at least partially surrounds the plug-in region. An attachment flange fits the plug connector and has an insertion region designed as a hollow cylinder, wherein the inner region of the hollow cylinder has at least one step, which forms two different regions each having different inside diameters, wherein the inner region of the insertion region is unthreaded.