Insulators are composed of ceramic components and upper and lower metal attachments bonded together with adhesive. The contact areas between the ceramic component ends and the metal attachments are lined with elastic pads. The bonding sections of the ceramic components feature structures such as sandblasting, knurling, and grooving for mechanical strength, anti-loosening, and anti-twisting. The ceramic surfaces are uniformly coated with white glaze, while the metal attachments are coated with gray magnetic paint. The main structure of the ceramic components of insulators comes in two types: a hollow partition (penetrable) structure and a solid (non-penetrable) structure. The bonded pole insulators are generally of the solid non-penetrable type. This latter structure offers improved performance and reduces maintenance testing work compared to the former. The ceramic components of insulators have either a multi-angled or a single-angled shape. The multi-angled shape increases the surface distance and has better electrical properties than the single-angled shape. All products except for the gradually phased-out external bonded pole insulators are of the multi-angled type. The internal bonding structure, due to the metal attachments being bonded into the ceramic holes, increases the insulation distance and improves electrical properties, while also reducing the space required for installation. However, since internal bonding is not conducive to increasing mechanical strength, insulators with high mechanical strength requirements are best suited for the bonded assembly type (i.e., the upper attachments use internal bonding, and the lower attachments use external bonding).