Composite insulators, also known as synthetic insulators, are made up of an insulating component consisting of a glass fiber resin core rod (or tube) and an organic material sheath and hood. They feature small size, light weight, high tensile strength, and excellent resistance to pollution and flashover. However, their resistance to aging is not as good as that of porcelain and glass insulators. Composite insulators include rod-type suspension insulators, insulating crossarms, pole insulators, and hollow insulators (i.e., composite sleeves). Composite sleeves can replace porcelain sleeves for various electrical equipment, such as transformers, lightning arresters, circuit breakers, capacitor sleeves, and cable terminations. Compared to porcelain sleeves, they offer higher mechanical strength, lighter weight, and smaller dimensional tolerances, as well as the ability to avoid damage caused by shattering.