Polipar externally gapped line arrester (EGLA) has two basic components, the Metal Oxide Resistor (MOR) and series gap. The MOR has roughly the same characteristics as a standard MOV arrester. The gap is generally a single air gap in series with the arrester.

• No leakage current, since the series gap disconnects the arrester part of the EGLA - metal-oxide varistor (MOV) blocks - from the system voltage under normal service conditions
• Lower arrester rated voltage required (arrester is not energized all the time, i.e. it's insulated by the series GAP)
  --> less material and fewer MOVs are needed
• No disconnector and no ground lead are needed
• Suitable for multiple-circuit towers with short clearances - the highly compact design of the EGLA and the absence of a ground lead allow installation and lightning protection even on towers with very small cross-arm clearances
• Better suited for live installation
• Complete EGLA solutions with polymer insulators also available
• Designed and tested to comply with the latest IEC 60099-8 standard