My Bernina Stitch Regulator came with my machine. Probably I would not have bought it if I had had to pay for it separately, but I love it now. I've free motion quilted many a quilt with it and I love how I can go really slow on a fussy part and then buzz around to the next fussy part. Sometimes I go so fast that it can't keep up with me. The stitches just get a little bigger then, but all in all it works great.