I find the CCDT67 to be a great reducer. Not only does it reduce with plenty of backfocus (85mm) and variable reduction if you are off, but it also flattens the field somewhat up to 29mm
diameter (fine for many ccds).
It is able to attach to a 2" nozzle allowing it to enter the drawtube.
For the low price this is very good value.
I bought mine from
here.