Yes, that's a retainer.

by R. Proffitt Moderator - 11/8/12 9:05 AM

In Reply to: dvv f by joejbuck

You see the slots on that? That's so you can press the four parts inwards and it releases.

I love literal interpretations. How did you get a picture of this computer if you were without this computer?
(no need to answer.)
Bob