Thimblelady's revolutionary New Design for whipstitch hand piecing! No pinching pain on the non-sewing hand. No paper basting needed. Perfect stitching simply beyond the best of your hands and eyes combined! Watch video demo  to see how it works for yourself. Dimensions of L regulators: 50mm x 100mm x 4.5mm; Dimensions of S regulators: 25mm x 100mm x 4.5mm. Both L and S regulators produce the same fine stitches (1 mm space, 0.5 mm depth). The functional difference between the L and S regulators are that L is designed to hold piece projects with batting already in it.  e.g. Magic Square project or any other quilt-as-you-go projects. Size S is designed to hold layers of piecing projects without batting in it. e.g. any and all hand piecing projects that are quilt top only. Using Size S regulators to piece your hand piecing projects can eliminate all the pintching pain on your non-sewing hand (particularly the pains in the area below the thumb); The super perfect whipstitching adds a great feature to your pieced work if you piece from the right side of fabrics. Once you start to follow the regulators to stitch, you can produce perfect stitches without pain nor good lighting (reduce strains on eyes). Perfect stitching tools for travelling quilters. A set of both L and S will cover all your piecing needs. Each regulators come with lavishly illustrated instructions. Go to Group Discount Page for bulk discount if you have a group of quilting friends.