They provide a long insulating path between the metal fittings to protect against electrical leakage and flashover.

A wide range of sizes and strengths are available. Greater strengths and leakage lengths are attainable by combining insulators into assemblies.

The ceramic is available in a clear or brown glaze finish with marking as an option. Metal end caps can be supplied as a single or double loop in manganese, silicon, or aluminum bronze, anodized aluminum, stainless steel or galvanized malleable iron.

Corrugated insulators can be designed to provide a longer leakage distance.