CORDURA Fabric: Weather resistant and incredibly tough fabric with rugger zipper closure. STORAGE: Four internal writing instruments pockets, one pen refill pocket, and more. INTERNAL POCKETS: Perfect for storing other field equipment and other important take along information. DESIGNED: Specifically designed for 4 5/8″ x 7″ Ring binders, 1/2″ Capacity Products. ORGANIZATION: Rely on Rite in the Covers to keep your notes safe and sound through thick and thin.