Mayline Vertical Plan Files are the ideal choice for economical, mobile filing of active documents. Document binders have an easy-to-use clamp that grips sheets securely without punching or stapling. Mayline Clamps and Pivot Hangers have been designed to be interchangeable with the systems of other manufacturers, so you can easily integrate Mayline components into your existing system. Perfect for engineering and construction applications. Limited lifetime warranty. Solid steel knobs and spring clip for maximum durability. Each clamp holds 100 sheets. Steel wing knobs turn for easy opening and secure closing. Packed six per box. Limited lifetime warranty.