Cardinal SuperStrength Locking Slant-D Ring Binder, 4-Inch, with Label Holder, Black (11822V2) Extra-firm locking mechanism to prevent spills and eliminate all gaps Easy-to-grasp oversize trigger Slant-D rings hold 25% more than standard round rings Patented Expand-A-Pocket in back holds an additional 1/2-inch stack of paper DataGuard inside pocket protects documents from ring impressions