The BERNINA Stitch Regulator (BSR) produces neat, consistent stitching with stitches of precisely the same length while free-motion sewing. Reacting to the movement of the fabric, it adjusts the speed of the machine automatically when free-motion quilting with the feed dogs lowered. The BERNINA Stitch Regulator (BSR) can sew both straight- and zigzag stitches. It is superbly suited to ambitious professional-level sewing projects on all fabrics -- the absolute star of free-motion quilting! Perfect for free-motion quilting with a controlled stitch length; the sewing speed adapts automatically to the speed of the moving fabric; automatic control of the stitch length ensures absolutely even stitch formation. For 5.5 mm & 9 mm machines with BSR function.