This file is from Wikimedia Commons and may be used by other projects.
The description on its file description page there is shown below.
Summary
DescriptionCeramic electric insulator.jpg
English: 10 kV ceramic pin insulator. This is used for insulating electric power distribution lines where they are supported by utility poles. The insulator mounts on a pin sticking up from the crossarm of the pole. The power line is tied to the top. It is moulded in a series of concentric disk shapes to increase the surface distance (creep length) along the insulator from one end to the other, to reduce surface leakage currents and also reduce the chance of flashover arcs.
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the licence, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible licence as the original.