Although the majority of collectors collect mainly glass insulators, there are a number of people who collect porcelain ones as well.

Dyar used apothecary vial jars as glass insulators for the bare iron wire.

Some insulator manufacturers stopped making glass insulators in the late 1960s, switching to ceramic materials.

The first glass insulators used in large quantities had an unthreaded pinhole.

They also made electrical glass insulators, however few were sold and they are a very rare collector's item.

His desperately kicking feet touched the metal support pole within the glass insulators.

Did I not stand two hours upon a glass insulator while you poured electricity into my body?

For instance glass insulators are sometimes used on very large (tall as a house) capacitors or the capacitor may be packed in oil.

In one corner stood a heap of purple and green glass insulators from telephone poles.

They originally made glass insulators for electrical lines.