Insulator 4 : Anything that prevents the exchange of electrical energy, such as plastic coating on wires, or glass or porcelain devices used to keep hightension (high-voltage) wires apart
Masters of Disaster, Lightning Glossary, The American National Red Cross (and Arizona State University), Washington, DC, USA 2007. http://www.azpbs.org/mastersofdisaster/pdf/Lightni ng/LightningGlossary.pdf, (Lghtng Sfty - Amer) {865}