This is an indispensible and handy tool for anyone who sews with a sewing machine. Use it to position your machine's needle exactly where you need it as well as to check the accuracy of you needle's position. Position the needle perfectly with a scant 1/4in 3/8in 1/2in 5/8in or 3/4in seam. It has a ruler with markings to 1/8in and the 45-degree end is very useful when piecing your binding strips together.