3/16" open end wrench that came with APPLE II add-on circuit boards
Seems like we've seen one of those here in the past.
I did a site keyword search for "Apple" and got a "not found .... "
It is in a March thread, but you are the one that mentioned it LOL
http://www.papawswrench.com/vboard/index.php?topic=10621.0
papaw found a picture on ebay to match...
(Forum site search is close to useless, but google can be coerced (sometimes) into searching a site)