Composite insulators, also known as synthetic insulators, are made up of insulating components consisting of a glass fiber resin core rod (or tube) and a jacket and hood made of organic materials. They are characterized by their small size, light weight, high tensile strength, and excellent anti-pollution flashover performance. However, they are less resistant to aging than porcelain and glass insulators. Composite insulators include rod-type suspended insulators, insulating crossarms, pole insulators, and hollow insulators (i.e., composite sleeves). Composite sleeves can replace porcelain sleeves used in various electrical equipment, such as transformers, lightning arresters, circuit breakers, capacitive sleeves, and cable terminations. Compared to porcelain sleeves, they offer the advantages of high mechanical strength, light weight, and small size tolerances, and can also prevent damage caused by shattering.