Sky Watcher 90mm Maksutov-Cassegrain

[Alienfox]

I have now had my SWMC 90mm for a couple of weeks now and have been awaiting the arrival of my laser finder & diagonal mirror, so now I am ready to go I notice that it has a ring at the base of the eyepiece mount (see image below) and have no idea what its for, the scope never had a manual and I cant find on on the net so can anyone help?  Please.

Thanks

[Steve Ward]

It just holds the optical back in place.

[Alienfox]

OK, Thanks Steve.

[dweller25]

And by slightly loosening, it allows you to adjust the position of the setscrews if they are in an awkward position.