A composite insulator is an electrical insulating device made of multiple materials. The most common type of strain insulator is the porcelain-housed, metal-ended unit used on high-voltage power lines. The word “composite” simply refers to the fact that these insulators are made of multiple materials. In a typical unit, there is an inner core made of glass or porcelain, surrounded by an outer housing of metal or plastic. The materials are joined together using an epoxy resin, which forms a bond that is stronger than the individual materials themselves. The main advantage of composite insulators over other types of electrical insulators is their superior strength. Because they are made of multiple materials, they can withstand higher forces without breaking or deforming. This makes them ideal for use in high-voltage applications, where they are subject to high levels of mechanical stress.