Fadenkorrektur; based on File:Fadenkorrektur_Thermometer1.svg and File:Fadenkorrektur_Thermometer2.svg; from User:Werneuchen
<a href="//commons.wikimedia.org/wiki/User:ILA-boy" title="User:ILA-boy">ILA-boy</a>
GPL
<span class="int-own-work" lang="en">Own work</span>