UNIQUE CREATIV Adjustable Magnetic Seam Guide helps sew straight, repeatable seams on mechanical machines with steel throat plates. The stainless steel guide attaches magnetically and can be positioned for common allowances, including 6.4 mm (1/4 in) quilting seams and 12.7 mm (1/2 in) garment seams. It supports piecing, topstitching and long seam control. Do not use on computerized machines.