the "I" is just a plug. It allows no air to get in the tube, and therefore, water only.
The "II" is open to the cup. It basically just acts a muffler to keep it a bit quieter.
, perfect is clear water at the O ring and bubbles above in the neck of the cup.
You won't get anything for a few days (at least I didn't). After it "breaks in" you will start getting nasty brown bubbles at the top of the neck. This is "dry foam" loaded with the protien you don't want. The cup should slowley fill, maybe an 1/8" a day.
You'll know it's working when you empty it; it reeks!
If you end up getting the cup filled rapidly with clear, or nearly clear water. It's flowing too much...
If after a few days, you have nothing in the cup, it's running too slow...