A device installed between conductors of different potentials or between conductors and grounding components that can withstand voltage and mechanical stress. There are various types of insulators with different shapes. Although there are significant differences in the structure and appearance of different types of insulators, they are all composed of two main parts: insulation components and connecting fittings.

Insulators are a special type of insulation control that can play an important role in overhead transmission lines. In the early years, insulators were mostly used for utility poles, but gradually developed to include many disc-shaped insulators hung at one end of high voltage power line connection towers to increase the creepage distance. They are usually made of glass or ceramic and are called insulators. Insulators should not fail due to various mechanical and electrical stresses caused by changes in environmental and electrical load conditions, otherwise insulators will not have a significant effect and will damage the use and operating life of the entire line.