Have you already heard about electrical insulators, but would like to understand more about it? The first step is to understand that it is materials that easily allow the flow of electrical charges inside due to a large amount of free electrons. Some materials that can be considered in this category are: silicone, glass (ceramics), plastic (resins), rubber and oil. These electricity insulators have high resistance to the load-flow, therefore it is used to cover copper electrical wires and cables.http://www.eastceramic.com/suspension-insulator/