Sew Easy Guide 2 (11 1/4") for Sewing Diagonally Across Squares (Up to 7 1/2"), Half Square Triangles, Quilt As You Go Seams Attaches to presser foot (won't harm foot) Removable and re-usable. For squares with sides up to 7 1/2" Save time and money ~ No marks to make or erase! No paper to buy or tear away!