About 100KV, vacuum tube tesla coil
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/152632095@N05">Dmitry Eliuseev</a>
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/152632095@N05/33402263496/">High Voltage: tesla coil, home experiment</a>