quick cuff is a different system than the QCS, the PU ring in the suit is larger. RoLock 90 goes with the QCS and they have a standard which goes on glued in latex seals.Well not quite so much. I have the SiTech quick cuff on my suit and the Rolock piece is way too small to fit into the suit. Also it is really really tight, to turn to lock the two pieces together, I would need a second person to help get it apart.
Bill
the tightness is often related to to much lube.