An additional coupling would be required for all extra powered implements.
If the implements are not powered, for example, the snow plough, then a blank coupling would be required instead of the additional coupling.
Please note: The BCS 660 and 750 power units have inbuilt implement quick coupling, so the additional coupling required is a different system. See here for details. This also applies to the CAMON C15.
Which power units is the additional coupling suitable for?