Gerbing Dual Controller Question

[Cougar]

Is the Black knob with green light the main source on the

Gerbing Dual Controller and the Grey (yellow light) is for the add on gear?

or does it even matter what one you plug into

 

I have just finished installing the Gerbing 12V Permanent Duel Temp Controller

to the back side of the lower fairing. easy to reach.

 

Now to sell my portable duel controllers not sure if I will need them

 

Thanks for any input !

 

Jeff