Insulators are categorized by installation method into suspended insulators and post insulators; by the type of insulation material used, they are divided into porcelain insulators, glass insulators, and composite insulators (also known as synthetic insulators); by voltage class, into low-voltage and high-voltage insulators; by environmental conditions, into pollution-resistant insulators for use in dirty areas; and by voltage type, into DC insulators. There are also various specialized 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 further classified into A-type non-breakdown insulators and B-type breakdown insulators.