I also bought this ruler thinking it was a 60 degree ruler. It is not....
Until I got this ruler I had to make my 54-40 blocks using paper piecing to get the points to come out properly. This set of rulers has the perfect little clip to line up the star points and have them come out the right size.
I purchased this ruler because it was listed as 60 degrees in the Joann's Store. I discovered, after ruining my material, that it measures 57 degrees. NOTHING MATCHED UP!
I went to a quilting seminar a couple of months ago, here in NH. It was the best. I just love working with them. There are so many things you can do with these rulers. With the Tri-Rec rulers and an imagination, you can go anywhere. I Love It.