Supporting conductors: In overhead transmission lines, post insulators bear the weight of the conductors efficiently.

Preventing current back to ground: Ensuring that live conductors do not experience current back to the ground, significantly protecting system safety.

Isolation: In substations and electrical equipment, these are used to support and isolate conductive parts, preventing critical electrical faults.

Material Composition: Typically manufactured from high-quality ceramic, glass, or composite materials, often integrated with metal accessories such as steel feet and iron caps.

Non-Penetrating Performance: Most post insulators employ a "non-penetrating" design, where the external flashover distance and the internal insulation capacity are balanced. In fault conditions, only external flashover occurs, avoiding internal dielectric breakdown.

Composite Advantages: Composite post insulators offer lightweight properties, superior shock resistance, and exceptional performance against pollution flashover.