Slant-D Locking Ring Binder holds 25 to 50 percent more paper than standard round-ring binders. Premium Slant-D locking rings secure contents and keep rings aligned. Patented Expand-A-Pocket on the inside back cover expands to hold up to 1/2" stack of materials. Patented DataGuard pocket inside the front cover prevents document damage from rings. XtraLife Hinge and BlindEdge Weld help the binder stands up to years of use.