An official power supply for the Action Max video game console.  The Action Max originally runs on 4 C batteries, so the power supply was an optional purchase that wasn't bundled with the system.  This power supply is model 4111 A9 and outputs 9V at 500mA.
<a href="//commons.wikimedia.org/wiki/User:Evan-Amos" title="User:Evan-Amos">Evan-Amos</a>
<span class="int-own-work" lang="en">Own work</span>