Single-Touch Locking D-ring Binder features a cover made of tough, eco-friendly polypropylene material that is tear-resistant. Exclusive Locking No-Gap D-Rings are designed for simple, convenient assembly of your materials, opening and closing quickly with a simple touch. D-shaped rings provide a higher sheet capacity so you can fit 750 letter-size sheets in the 3" capacity. Locking mechanism assures the rings will stay aligned to prevent papers from falling out, even when fully loaded. Metal rings are back-mounted so pages lie flat. Premium binder also includes exposed rivets.