The bottom side of a tower cooler (“Nordwand” by Alpenföhn) in which the <a href="https://en.wikipedia.org/wiki/Heat_pipe" class="extiw" title="en:Heat pipe">heatpipes</a> are incorporated in the base of the cooler
<a href="//commons.wikimedia.org/wiki/User:D-Kuru" title="User:D-Kuru">D-Kuru</a>
CC BY-SA 3.0 at
<span class="int-own-work" lang="en">Own work</span>