True "Gapless" binder allows pages to turn smoothly without falling out. Pages flow smoothly because patent-pending, one-piece rings have no gaps. Individual rings snap securely into their base and will not open when the binder is dropped. Rings canlie flat when not in use, which maximizes storage space and makes the empty binders easier to transport. Binder offers interior pockets. Heavy-duty cover is made of 32mm board.