SAC color filter wheel questions

In my search for a low cost color filter wheel, I see that SAC imaging has
such a unit. Has anyone here had any experiences with it and how do you
like it? My camera has a C/CS thread. Anyone know if the SAC wheel will
couple to it?

My other question concerns the optical train length. How do color filter
wheels, like this one, change the focal length of the system when I am using
a standard 3x barlow also, along with the wheel and ccd camera?

Thanks,
BS