Hi,
I have a set on the C8, after pinging the corrector plate with a screwdriver in the dark (just a slight touch, but wow)
I agree with Andy, they are way overpriced for what they are, but very very useful to have. I like to collimate a bit each time, and that is now a breeze, using the Knobs and this resource
http://www.asterism.org/tutorials/tut14-1.htm
Maybe you can find an alternative (I never bothered) somewhere like
http://www.smallparts.com.au/store/p...teners/wide/1/
Cheers