Locking Slant-D® rings secure binder contents and keep ring wires aligned. Holds 25% - 50% more than conventional round ring binders. Made from the heaviest vinyl in the industry. Expand-A-Pocket® in back expands to hold up to 1/2" stack of materials. Exclusive DataGuard™ Pocket inside front prevents document damage. Stands up to years of use with XtraLife® Hinge and BlindEdge™ Weld. Flat poly sheet lifter turns pages over rings easily.