
So now I have a nob question:

I was looking at the SuperFlow SP-600 and I noticed on the far left what appears to be two large 48" manometers. I'm assuming one is for the test pressure. What is the second one for? Or is it only one? The spec sheet says it only has one. I'm confused.

I'm not talking about the sloped manometer in the middle used to calculate air flow, but the very tall ones on the left of the machine.
You can see both of them in this picture:

Sorry if this has been asked before.
Thanks in advance. Take care,
David