Orbit 69000D 8-Port Drip Manifold with Adjustable Flow

How do you adjust the center dial and does it do? And how do you adjust the individual ports? Which direction do you turn to increase flow?

I cannot see the "easy to access" filter, where is it and how to get it out?

If the 1/4 inch tubing you are running from the manifold goes out several feet has that caused anyone issues water pressure wises??

I need the caps that go on this manifold. Are they sold on Amazon?