The guide makes it much easier to insert zips straight and to topstitch edges. Zipper Foot with Guide #14D is suitable for the precise, professional insertion of zippers. It resembles standard Zipper Foot #4, but features an added bar across the top of the foot which serves as a guide. Professional sewing on of zippers percicsly sew zippers of all sizes. Owing to its wavy shape, this Adjustable Guide rides right over the coils of the zipper. The result is a neat, evenly inserted zipper. And with its ability to produce perfectly parallel lines of straight topstitching, Zipper Foot with Guide #14D is is also a useful aid when edge stitching.