Quote Originally Posted by MattKing View Post
The clips for the 645 Pro and Super are entirely proprietary - there is no 3rd party substitute that will work (including Optech USA). The problem with 3rd party straps is that the connection clips interfere with winding (either the manual winder, or the power winder) on the right side of the camera.

If you have the clips, I believe that you can feed 3rd part strap material (of the right size) through them, but I haven't tried it.

This is what I've read too, and it's another strike against the Optech. It would be nice if I could find a pair of the Mamiya clips somewhere. I don't really fancy the idea of buying the whole strap only to use parts of it. Though i saying that I might really like it.