This plug is a bad construction. It is sometimes difficult to insert the cable because of the way it is constructed - the socket hole closes as you screw up the screw, because the socket part moves out of the plastic shell as you open the screw.. Hard to explain.. But you can use only very thin cables and it is troublesome.
Moreover, the general quality is poor, it even degrades sound compared to the more standard black round 2-pin DIN plugs. I recommend these instead!
I wish there were high end 2-pin DIN plugs, for us who are vintage audiophiles..