ST tracer lift/regulator arm, Lohr industrie. Drawing used to determine graphically the height of lifting.
<a href="//commons.wikimedia.org/wiki/User:Cdang" title="User:Cdang">Cdang</a>, from the french exam BTS CPI, session 2011, épreuve E51
<span class="int-own-work" lang="en">Own work</span>