The ones for the plastic or glass section? One fits in a groove about 1/4" above the windows and the other goes in a groove about 1/4" below the windows.
Okay, I don't see any o-rings in there. I'm assuming I'd put the clear o-rings that came in the part kit into it but they're too large and there's always a piece of it that sticks out (i.e. doesn't sit flush.) I am pretty sure that's where my leaking issue is coming from because when I blow into the top piece alone while covering the end, its not air tight.