Cooper Wheelock logo.
Cooper Industries
<a href="//commons.wikimedia.org/wiki/File:Cooper_Wheelock_logo.jpg" title="File:Cooper Wheelock logo.jpg">File:Cooper Wheelock logo.jpg</a> and <a rel="nofollow" class="external autonumber" href="http://www.cooperindustries.com/content/dam/public/safety/notification/Resources/Specification%20Sheets/Wheelock%20ET80%20and%20ET1010%20Speakers.pdf">[1]</a>