Playback head can of prototype reel-to-reel tape machine produced by Salford Electrical Instruments (a division of General Electric Company, hence the GEC logo on the panel).
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/30661871@N03">Richard Ash</a>
CC BY-SA 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/30661871@N03/32658405598/">IMG_5615</a>