<p><a href="https://en.wikipedia.org/wiki/Ohio_Scientific" class="extiw" title="en:Ohio Scientific">Ohio Scientific</a> <a href="https://en.wikipedia.org/wiki/Challenger_2P" class="extiw" title="en:Challenger 2P">Challenger 2P</a>, with optional double disk unit.
</p>
On display at the <a rel="nofollow" class="external text" href="http://www.bolo.ch">Musée Bolo</a>, <a href="https://en.wikipedia.org/wiki/EPFL" class="extiw" title="en:EPFL">EPFL</a>, Lausanne.
<a href="//commons.wikimedia.org/wiki/User:Rama" title="User:Rama">Rama</a> &amp; Musée Bolo
<span class="int-own-work" lang="en">Own work</span>