Get premium features, a higher sheet capacity, extra pockets and the best durability with Ultra Duty binders. Ultra Duty combines our best ring with the strongest covers made by Wilson Jones® for unmatched ease of use and strength. D-Lock™ rings with a Single-touch trigger keep papers secure yet are so easy to open that you can use just one finger. Ultra Duty covers are made from custom-formulated PVC-free polypropylene which lasts up to 10x longer than a vinyl and is more eco-friendly.