For your bigger DR rings (108, or 125) and 80mm guidescope. Scope must have double set screws for the focuser and also a focus lock. Must also hold an ST-4 without flexure.
I want to try a bigger guidescope to guide my TV-85 on the GM-8. That also means I need bigger rings. My equipment is in good condition, although these rings have no delrin tips.
For this bright Moon period I'd like to try to trade (with a little extra cash of course). Next month I will sell this outright to pay for the larger scope and rings.