The insulators are made by bonding porcelain components with upper and lower metal attachments using adhesive. The porcelain component ends are in contact with the metal attachments via elastic pads, and the bonding areas of the porcelain components feature structures such as sandblasting, knurling, and grooving for mechanical strength, anti-loosening, and anti-twisting. The porcelain surfaces are evenly glazed white, and the metal attachments are coated with gray magnetic paint. The main structure of the porcelain components of the insulators consists of two types: a hollow partition (penetrable) structure and a solid (non-penetrable) structure. The combined bonded pillar insulators are generally of the solid non-penetrable structure. This structure reduces maintenance and testing work compared to the previous one. The main structure of the porcelain components of the insulators can also be a hollow partition (penetrable) structure or a solid (non-penetrable) structure. The combined bonded pillar insulators are usually solid non-penetrable. The porcelain components have two shapes: multi-angled or less-angled. The multi-angled shape increases the surface distance and has better electrical properties than the less-angled shape. All products except for the gradually phased-out external bonded pillar insulators are multi-angled. The internal bonding structure, due to the metal attachments being glued into the porcelain holes, increases the insulation distance and improves electrical performance, while also reducing the space required for installation. However, since internal bonding is not beneficial for increasing mechanical strength, insulators with higher mechanical strength requirements should use combined bonding (i.e., the upper attachments use internal bonding, and the lower attachments use external bonding).