High power gas discharge tubes marked with Ex are suitable for use in explosion hazardous areas, where ensure the equipotential bonding between inactive parts, which are not conductively interconnected due to the operating conditions. Recommended for insulated flanges and insulated screw joints bridging in cathodic protected parts of industrial technology. In case of origin of potential difference between those parts, the high power gas discharge tube ignites and interconnects both insulated parts for a transient time. High protection degree of the housing allows using indoors, outdoors and also in the underground. Suitable construction prevents the formation of sparks and minimizes the release of heat generated during the discharge of the highest lightning impulse current.