Bus duct penetration, awaiting <a href="//commons.wikimedia.org/wiki/Firestop" title="Firestop">firestop</a>.
<a href="//commons.wikimedia.org/wiki/User:Achim_Hering" title="User:Achim Hering">Achim Hering</a>
2006-11-10
<span class="int-own-work" lang="en">Own work</span>