Tube module from an IBM mainframe.
From the collection of the RCS/RI.
<bdi><a href="https://www.wikidata.org/wiki/Q18857750" class="extiw" title="d:Q18857750"><span title="computer museum in Providence, Rhode Island">Retro-Computing Society of Rhode Island</span></a>
</bdi>
<span class="int-own-work" lang="en">Own work</span>