I have one for a Schon. As I ordered it last December they sent I think a standard insert. It's slightly loose going on, but tightens up really great. If ordering again for a Schon, I would get their tighter joint. Fantastic shaft, so much so I ordered another in 12.5mm same as before. Never did get that shaft. After numerous tracking #'s that actually never were, and numerous excuses, lost in the mail, will send another, I finally had had enough after more than a month of excuses and gave them a deadline of three days to show me that the shaft with the latest tracking # was actually picked up and enroute. They couldn't do that and refunded my money.
While I still, even after all of this, still want another shaft from them, I see I would have to change the diameter as soon as my money was returned the 12.5 has no longer been available on their web site. I now see why I was never able to get my shaft from them even though I was given multiple tracking #'s.