Insulators are composed of glazed ceramic components and top and bottom metal accessories bonded together with adhesive. The glazed ceramic ends are in contact with the metal accessories, which are lined with elastic pads. The glazed ceramic bonding sections feature structures such as sandblasting, knurling, and grooving to enhance mechanical strength, prevent loosening, and twisting. The ceramic surface is evenly glazed white, and the metal accessories are coated with gray magnetic paint. The main structural types of ceramic insulator bodies include hollow partition (breachable) and solid (non-breachable) configurations. Composite bonded pillar insulators are generally solid and non-breachable. The latter structure is an improvement over the former, reducing maintenance and testing workload. Insulator ceramic components come in two shapes: with or without ridges. The ridged shape increases the surface distance, offering better electrical performance. All products except the externally bonded pillar insulators that are being phased out are of the ridged type. The internal bonding structure, where metal accessories are glued into ceramic holes, increases the insulation distance, enhances electrical performance, and reduces the space occupied during installation. However, due to the negative impact of internal bonding on mechanical strength, insulators with high mechanical strength requirements should use composite bonding (i.e., upper accessories with internal bonding and lower accessories with external bonding).