The Half Rectangle Trim Tool from Creative Grids makes half rectangle units in seven different sizes. Make the half rectangle units with either a right or left slanting seam. Cutting chart is printed right on the tool, along with trim lines for perfect half rectangle units every time. A & B trims make it easy to line up the triangles for sewing. Since half rectangles have a different angle than half square triangles, an extra 1/8" indent is added in the final trimming so that when sewn into a project, the seam lines will go corner to corner.