Samsill DXL/Contour Cover Ergonomic Binder, D-Ring, 3-Inch, Black (17680) Your Perfect Fit! Designed for comfort, a professional look and oversized function. Curved back spine provides comfort grip Compact design easily houses over-sized indexes and sheet protectors without overlap Soft Click locking D-ring - opens with one simple motion Stronger hinge for constant use; created with a special ribbed seal