Surge arresters are classical components for protecting the installations of the telecommunications. It is essential that IT and telecommunications systems -with their high-grade but sensitive electronic circuits – be protected by arresters. They are thus fitted at the input of the power supply system together with varistors and at the connection points to telecommunication lines. They have become equally indispensable for protecting base stations in mobile telephone systems as well as extensive cable television (CATV) networks with their repeaters and distribution systems.

These protective components are also indispensable in other sectors:
● In AC power transmission systems, they are often used with current-limiting varistors
● In customer premises equipment such as DSL modems,WLAN routers, TV sets and cable modems
● In air-conditioning equipment
The integral black-box concept offers graduated protection by combining arresters with varistors, PTC thermistors, diodes and inductors to create an ideal solution for many applications.