The SCA 331 is the shoe that slides onto the Metz flash units and adapts from the Minolta hot shoe to the contacts on the flash unit. The SCA 307A is a cord that slides into the flash unit and replicates the flash unit contacts at the other end of the cable, then the SCA 331 slides into that end of the cord and is used in the hot shoe. None of this will get you the use of a Minolta flash unit off-camera.
Originally Posted by pbromaghin
This page should help finding out what you need. Probably the Cable OC (OC = Off Camera).