The Good Measure name represents a high quality and accurate measuring system and the good that comes in the form of a donation to breast cancer research for every Good Measure Ruler sold. Make a difference while making something beautiful. Feel good about your choice to purchase Good Measure Rulers - the only rulers with a cause. This Side Set Triangle ruler simplifies the creation of the tricky side units and corner units needed to set a quilt on point. The Side Set Triangle ruler works off the height of the unit. This ruler does not cut an exact size, but rather an approximate size, You will have extra fabric to square up your pieces perfectly. All Good Measure rulers are designed to be compatible with each other, ensuring accurate cuts and allowing you to utilize these rulers for all your cutting needs. Each ruler is labeled with its size or the name of the specific job it does. Good Measure rulers are accurate, easy to read and versatile.