Wire-O binding wire, also called "duo-wire" or "twin-loop binding wire," is a versatile binding spine that offers security and durability, but with style and affordability. 2:1 pitch wire-o binding wires are designed to fit the signature hole pattern of a 2:1 pitch wire binding machine (two holes per inch = 21 holes per letter-sized sheet). These binding wires have loops that are 5/8 inch in diameter. The wires are 11 inches in length and are designed to be used with Letter size documents. However, they can also easily be cut with wire cutters to accommodate books with spines smaller than 11 inches long and can then used with a binding machine equipped with disengaging pins. Wire-O binding wires from Rayson are fully compatible with all standard wire binding machines, including models from other office supplies who also sell the 2:1 pitch binding machines. These heavy-duty, metal binding spines are perfect for reports, presentations, calendars, sketchbooks, as well as other binding projects that require an additional level of sophistication. With 50 pieces per box, you can access wholesale binding-material pricing while purchasing the right number of wires for your needs. Whether you are binding a few books or hundreds, Rayson provides the quality of materials you need.