Reference binder features back-mounted rings for a clean professional spine. XtraLife hinge provides durability. Back-mounted design allows sheets to lie flat. Steel, nonlocking round rings also have dual opening & closing triggers for easy sheet removal & insertion of your letter-size papers. 1" ring capacity accommodates up to approximately 225 letter-size sheets. Two horizontal pockets on the front & back covers secure loose, unpunched documents. Each pocket holds 40 sheets. Design also includes exposed rivets & a sturdy chipboard core.