What is this?

[northcanadian]

Hi folks

I notice on my 9.25 sct (xlt) something on the secondary mirror housing (where collimating screws are).  There are two opposite small square openings which look like glass behind them.  One has a thin red verticle bar (looks like a meter of some sort).  I am wondering what this is and what does it do?

Thanks

Roger

[cutepetgroomer]

I'm not sure but I do know some reflectors have a mark that shows when then need collimating. I'm more familiar with refractors.

[Cornelius Varley]

Guessing, i think these are for locating a Hyperstar or Fastar compatible camera and relocating the secondary mirror.