Insulators connect the power lines to the utility pole and ensure that electricity remains in the lines. They are made of insulating materials, such as porcelain, glass or nonconductive polymers. Insulators are there to prevent electricity from escaping and traveling down the utility pole.
Step-down transformers serve to reduce the electricity from primary lines to a voltage more suited for customer use. These transformers are bucket shaped and can be found between the primary and secondary lines.
Regulators are special transformers that maintain specific voltage levels. They are generally rectangular.
Both transformers and regulators cool their internal components using oil, which can pose explosion, smoke and oil-release hazards. In the event of a fire, be aware of this danger.