Overhead wire marker

Overhead wire markers are safety instruments applied to the overhead power lines marking transmission lines and ropeways along the flight path during the day.

[1][2] Markers are often installed on overhead lines near airfields, or at river crossings where there is a possibility of float-equipped aircraft using the river.

Some markers contain conductor marking lights or strobe lights to improve visibility at night or in fog.

A spherical marker. Spherical markers are also known as aerial marker ball s.
Markers on a line near an airfield
An overhead line obstruction warning marker near an airstrip.