It is a combination of some devices to allow your chart plotter to depict your boats systems via NEMA2000. You can see things like power in (charger), consumption
, tank levels, and I believe your engine
I believe they use a some mastervolt components (like shunts) and some Czone components to read info from sending units and tie in the victron multiplus.
I saw a rough diagram I’ll see if I can’t dig up.