HGS100 and HGS100 EB are a separating high power gas discharge tubes intended for equipotential bonding of an installation parts of buildings, which are not interconnected. In case of origin of p.d. (potential diference) between those parts, the high power gas discharge tube ignites and interconnects both parts for a transient time (typical value of internal resistance at startup of HGS100 is 0,001 ÷ 0,002 ?). Recommended installation is inside of the buildings, outdoors, in the damp rooms as well as in the subterraneous areas. For lightning protection equipotential bonding in accordance with IEC 61024-1 as well as for the use in IT - installations in accordance with IEC 60364-5-54.