How do you measure RT60 in the latest REW?

Help says you can do this but not how. I've looked at all the tabs and can't find it. I looked in RTA and couldn't find it. This is probably pretty obvious if you know what you're doing but I don't.

I understand what it is I was trying to figure out how to see it in REW, I did a little more trial-and-error and worked it out. Turns out there is a drop-down menu I didn't know about on the measurement screen.