Need to give your reports, presentations, or booklets a professional, bound look? These RAYSON double-loop wire binding spines (also called Wire-O, twin-loop, or duo-wire) are perfect. They're 3/8 inch in diameter, have 21 loops, and use a 2:1 pitch (that's 2 holes per inch). They're designed for standard Letter-size paper (11 inches long) and can bind approximately 15 to 50 sheets (25-60 sheets, depending on paper weight). The silver finish looks sleek. You get a pack of 100 spines, so you'll have plenty for multiple projects. They work with compatible 2:1 pitch binding machines (like the RAYSON TD-1222). The double-loop design lets pages lay flat and flip smoothly—great for manuals, portfolios, or cookbooks. Made from durable metal that won't warp easily. Whether you're binding work documents, school projects, or personal photo books, these spines offer a clean, organized finish. A must-have for offices, print shops, or serious crafters.