My Bernina 440 does not have a serpentine stitch per say. I use the multi stitch zig zag that is for sewing on elastic. It does a few stitches in one zig and then a few stitches on the zag and when I open up the stitch length, it becomes the serpentine stitch. If any of your machines have a multi stitch zig zag, you have a serpentine stitch.