The CW shaft that my friend made for me for my CGEM mount cost less than half of what Criterion is asking for theirs and it has a 1" OD, not 20MM, or .787". This affords no flexing of the shaft at all and DOES make a difference in dampening. The original shaft that is on the CGEM is a 20MM shaft and only extends out 9" past the hub and it flexes with the amount of weight needed to balance the 11" celestron SCT. Extending that shaft by twice and leaving it at the same diameter only increases the amount of flex and thus less dampening. I am sure that Criterion is a very reputeble company but I believe their claim is flawed.