Binding capacity: 20-125 sheets of 20# paper. The margin size affects the number of sheets that can be bound. For example, margins of 2.5mm for 125 sheets, 3.5mm for 115 sheets, and 4.5mm for 105 sheets. Pitch 2:1 (per inch has 2 holes), 21-hole pattern; Length: about 11 inches for letter size sheet format; Including Color: Black, Gold, Blue, White, Silver; The wire coil can bind paper up to letter size. For smaller paper sizes, trim the excess wire with scissors. Durable double-loop metal combs guarantee long-lasting performance. The metal construction doesn't warp easily, and paper doesn't shift easily during binding, making it the first choice for binding important documents. Perfectly matched to the RAYSON TD-1222, 2:1 binding machine, the machine's accessories are excellent for helping you bind documents and paper, optimizing your time. These Wire-O binding wire, also called "double-wire" or "twin-loop binding wire," is a versatile binding spine, with 2:1 pitch and 21-loop are available in a wide range of sizes that offers security and durability, but with style and affordability. The wire binding spines 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 TD1222, perfect for binding reports, presentations and any other book binding projects.