Spiral coil binding offers both a professional, finished look to documents and a "lay-flat" design with the ability to flip pages 360° from front to back. Plastic coils such as these Premium 4:1 Pitch 12 in. book binding coils are an excellent high-quality choice for business proposals, annual reports, company presentations, restaurant menus and more! All Premium plastic spiral binding coils have a 4:1 pitch (4 holes per inch) and are fully compatible with any matching 4:1 pitch coil binding machine; models include brands such as Akiles, USI, GBC, Ibico, NSC, Tamerica, Fellowes, Rhin-O-Tuff, Renz, and HIC. hese book binding coils are available in a 12 in. length and are designed to be used with Letter size documents, leaving excess on either edge to allow for crimping the ends shut with pliers. These plastic spiral binding coils can easily be cut to accommodate books with spines smaller than 11 in. long and can then be used with a binding machine equipped with disengaging pins.