The Bernina 5.5mm width zig zag needle plate is designed for sewing on lighter weight material with a zig zag stitch or a decorative stitch. It helps to keep the material from pulling to the center of the stitch when doing zig zag stitches. This also is a smaller slot so when quilting it helps prevent the fabric from pulling down in the machine. Pair this plate with the 5.5mm pressure feet for best performance.