Insulators are categorized by installation methods into suspended insulators and pillar insulators; by the type of insulating material used, they can be porcelain, glass, or composite (also known as synthetic) insulators; by voltage class, they are divided into low-voltage and high-voltage insulators; by environmental conditions, there are dirt-resistant insulators for polluted areas; by voltage type, there are DC insulators; and there are also special-purpose insulators such as insulating crossarms, semiconductor glaze insulators, tension insulators for distribution, reel insulators, and wiring insulators, among others. Additionally, based on the possibility of insulation breakdown, they can be classified into two types: A-type, non-breakdown insulators, and B-type, breakdownable insulators.