This is the Complete Set of curve rulers, 6 rulers in all. Great gift for any quilter and an awesome set of curves to have in your arsenal to get those tough designs and motifs stitched.These ruler is fantastic for blocks and varying border designs, and is incredibly helpful in stitching curves. great base for marking larger feather motifs and getting around those curves nicely. Ruler is 1/4″ thick and can be used on Domestic or Lonagarm Machines. rulers have the same degree curve along the top and bottom; what this means for you when quilting, is that you can easily switch directions while quilting without having to switch hands for holding. The etched 1/4″ registration marks won’t wear off like printed on lines can features a green tinted acrylic which allows for better sight of ruler and registration markings on all colors of fabric, where as white lines may get lost when trying to see and line up registration marks on white and light fabrics) So many wonderful features you’ll wonder why you didn’t invest in these rulers sooner!