Air-termination mast with HVI power Conductor (high-voltage-resistant, insulated down conductor), for keeping the separation distance from conductive parts according to IEC/EN 62305-3 in order to prevent dangerous flashover between parts of the external lightning protection system and indoor conductive parts (electrical installation, pipes, etc.). In order to avoid creeping discharge, the HVI power Conductor has a special outer sheath which makes it possible to discharge high lightning impulse voltages to a reference potential. HVI power Conductor (black) with internal sealing end and an earth connection element. Conductor length 10 m. Equivalent separation distance s ≤ 90 cm (in air), s ≤ 180 cm (solid material).