What is the correct name of this part I need to replace?

[66-Overlander]

I'm not sure if it's a "ceiling vent" or "skylight". I have 3 vents in my ceiling. Two have fans and work great. The third is a manual crank rectangular plastic piece. The handles and cylinders work, the screen is there, the plastic piece moves, but has a bad crack in it and leaks. I just need to replace that plastic piece. I'd like to try and do it myself to save some money. Just wondering if anyone has found anything that works?
I know Inland has a piece to replace it, but it's $140 which is why I'd like to try to fix it on my own.
Any suggestions are most appreciated!
Thanks.
Callie

[upallnight]

Callie
Click on the link below and it will give you a little more info on what you are looking for.
http://www.airforums.com/forum...highlight=vent
Also welcome to the forums.