Removing the rear barrel the lens is completely "naked". The autofocus clutch has been removed in this image, it sits in the cutout in the front and drives the inner gear train on the main barrel. The graycode strip for reading the focus position is visible on the left. The copper sheet glued to the main barrel has the focus scale on it.
<a href="//commons.wikimedia.org/wiki/User:Phiarc" title="User:Phiarc">Phiarc</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>