The invention relates to a long-distance line for high voltage, having an outer jacket pipe extending in a longitudinal direction, having an inner conductor led in the interior of the jacket pipe in parallel to the longitudinal direction, and having a number of mounting insulators, by means of which the inner conductor is held on the jacket pipe at a distance therefrom transverse to the longitudinal direction, and a correspondingly embodied mounting insulator. The mounting insulators serve for adjusting the distance between the inner conductor and the jacket pipe. The long-distance transmission line is particularly air insulated in design. The mounting insulators allow simple assembly and installation of the inner conductor.