Tri-Recs Tools, by Darlene Zimmerman & Joy Hoffman, includes TWO 6" acrylic triangle tools and instruction booklet. The easy way to make triangles within squares and divided rectangles. Cuts many sizes of triangles an divided rectangles from even size strips of fabric. Compatible with Easy Angle and Companion Angle. 1/4" seam allowance included. Ideal for use with rotary cutter. The cut-off "Magic Angle" makes it easy to align and sew accurately.