Linda -
Yes, that’s the one. They also have a 4.5 by 18.5 (I think) that does all the same things.
I just went to the CG website and saw that several of their rulers have the opposing 45* that meet a quarter inch from the edge. If you don’t want to buy another ruler and you use CG, check some of your other rulers. I would imagine other makers have these markings as well. I do love this ruler though and it is always on my cutting table because I use it so much.