Yes, I have a set. You replace the entire rotating draw-length and string stop mod with a new pair. They are $100, and you can change them out yourself. Interestingly enough, for $100 you don't get an additional set of string stops so you have to move them back and forth from your high let-off to your low let-off versions. It's a really nice piece of engineering though, to have all that flexibility to not only have all the draw length adjustability, but the let-off capability as well without compromising your draw length and valley. The Prime Centurgy Hybrid (which I have on order), not only is your draw length fixed, so when you alter the let-off you cannot alter the draw length, you also loose valley when you go to the high let-off's. Prime says that at 65% let off, you have zero valley. It will be interesting to shoot it that way, I'm guessing I will hate it, but maybe it's really good for tension style release.