note: I could not remove the knob in the middle because the locking screw holding it will not turn. But I would assume the knob looks like the one at the left side of the device. At any rate, I can see right thru the device, end to end, after removing the left knob and the filter assembly.
sub-note: After disassembly, I was kinda pleasantly surprised that nearly all my assumptions on its design was correct. I even suspected a spring connected to the left knob before I drew my sketch.
After dismantling the unit, I only needed a minute to reassemble it (in fact, its on my desk serving as a very good paperweight again). And the left bottom screw-bolt is indeed holding the left adjustment knob to the body.
IMHO, if counterfieters really want to copy the device, all they need to make one is any good machineshop, no specialized skills necessary after that.
If both knobs must be white dot to white dot, then the spring actuated valve is totally unused. Basically in that setting, the device is in free-flow between the filter to the engine.
So how does the device
regulate 15:1 air-fuel ratio given the only thing left to regulate the amount of air thru it is the scrubbing pad filter?
I have been pretty much careful with my adjustable wrench and left no toolmarks on the device. Its as "clean" as it came off the vehicle. I doubt if they could detect anything wrong.