The main categories of zippers, as described above, also include speciality zippers, which have special types of construction, or parts, or finishes. CFC zippers have a special class known as Invisible zippers due to the special construction and mode of use. These zippers do not require the provision of a fly since they are made and stitched in such a manner that only a hairline seam is visible from outside. These zips are predominantly used in ladies dresses and skirts. These zippers are available in knitted and woven tapes.