Two Square Up Rulers in one! The Top Half works like a 4 1/2" Triangle Square Up. This portion is great to square up Half Square Triangles, Quarter Triangle Squares and Tri-Square Patches. Turn the ruler around and Square up any patch up to 6 1/2" inches. I think this will be your Go-To Ruler for most of your square up needs. Try it out and tell us what you think on Facebook.