This 1/2" x 9" seam marking tool is long enough to mark the diagonal of a 6-1/2" square. Mark through the slotted center with any mechanical pencil and sew 1/4" on each side of the tool.
Or mark the sewing line by drawing on both outside edges. Grip holds the tool in place while marking. The perfect tool when making half-square triangles!
Made in the USA.