This ruler cuts half square triangles perfectly every time. Use with NNQS (Nifty Notions Quarter Square) for perfect flying geese. Designed by Kaye England, this series of rulers will work together as a compatible set. These rulers read right to left and left to right and have perfect sight lines. But perhaps most important of all, a portion of the proceeds from each ruler goes to The Chicagoland Affiliate of the Susan G. Komen Breast Cancer Foundation.