What is called and what is it used for?

The main function of a power line vibration damper is to reduce the amplitude of the vibrations in overhead transmission lines caused by wind galloping or other environmental factors that can cause vibrations in the line conductors.

The Stockbridge damper is the most popular damper used for prevention of vibration in Transmission Line.

It is a tuned mass damper used to suppress wind-induced vibrations on

slender structures such as overhead power lines, long cantilevered signs and cable-stayed bridges.