Moroso catch/overflow tank questions.

I bought one today, at the suggestion of a friend, and...well, I don't "get it".

I suppose it is more of a catch tank, and doesn't work like an OEM does. With a hose at the top of the tank and no kind of "straw", how can the radiator suck coolant if it needs it?

Also, where/how should it be mounted...for those who have one?

Ok, nevermind. I was just assulted with a dose of common sense. I was looking online (after searching here first) and noticed that the valve is supposed to go on the bottom and the hose goes on top...which is opposite of how I thought it should go.

Then I found online where people put the hose on the bottom (like I originally thought) and then it works like the OEM one does. I guess I will just leave the top valve open with a small hose pointing to the ground....again, like the OEM one does.