Insulators are composed of ceramic components and upper and lower metal attachments bonded together with adhesive. The contact areas between the ceramic components and metal attachments are padded with elastic washers. The bonding areas of the ceramic components feature structures such as sandblasting, knurling, and grooving for mechanical strength, anti-loosening, and anti-torsion. The ceramic surfaces are uniformly coated with white glaze, and the metal attachments are painted with gray magnetic paint. The main structures of the ceramic components in insulators include hollow partition (penetrable) and solid (non-penetrable) structures. The bonded pillar insulators are generally of the solid non-penetrable structure, which reduces maintenance and testing work compared to the hollow partition structure. Insulator ceramic components come in two shapes: with or without multiple facets. The multi-faceted shape increases the surface distance, offering better electrical performance than the single-faceted shape, except for the external bonded pillar insulators that are being phased out. Most products are of the multi-faceted shape. The internal bonding structure, due to the metal attachments being glued into the ceramic holes, increases the insulation distance and improves electrical performance while also reducing the space required for installation. However, as internal bonding is not beneficial for enhancing mechanical strength, insulators with higher mechanical strength requirements should use the combined bonding method (i.e., the upper attachments are internally bonded, and the lower attachments are externally bonded).