Invisible zippers are the least noticable of all zippers. As the name implies, the zipper is hidden in a seam, becoming virtually invisible. This makes it a popular choice for elegant clothing sewn with expensive materials, like evening wear. But it's equally appropriate for skirts, blouses and other everyday clothing items. Invisible zippers (also called concealed zippers) are easily sewn with the Pfaff Invisible Zipper Foot! Fits C,D,E,F,G,J,K,L