I am wondering how to adjust the agency power 50/50 bov. I did search and couldn't find much, except for other people wondering the same thing. Please don't tell me how dumb i am for having a bov, just answer the question if you can..

-On top there's a round metal knob with texture around the outside for grip, and there's a sort of triangular shaped knob on top of that. What do each of them do? AKA, which way (tightening or loosening) goes closer to 50/50 or 100%atmo?
-Also, do they both adjust separate components, or does the round knob just act kinda like a locking nut for the triangular knob?

here's a good picture to look at for reference:

Any information would help thanks guys.