power amplifier.  Your engineer can build this onto your power generators to double the resource output of a region.

Can someone explain this?  Does this mean only one per region?  Or can you stack them on an power generator.  It could be that I am not understanding what the power generator is.  I am thinking that a generator is what we are building on top of the metal and radioactive stops.  Yeah, maybe I am just confused.

If you can't stack them, what happens if you tried to build more than one?  So what is doubled?  Metal or Radioactive?

Hopefully someone can explain this better.