EXP416
<p>Fairchild  silicon planar NPN dual matched transistors packaged in TO-79 metal can case
</p>
1973
<a href="//commons.wikimedia.org/wiki/User:Mister_rf" title="User:Mister rf">Mister rf</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>