A ring mechanism for retaining loose-leaf pages, the mechanism comprising a housing having a longitudinal axis, a central top portion, an open bottom generally opposed to the central top portion, and opposed longitudinal edges extending along the length of the housing. The housing has a plurality of separate openings defined therein spaced along the length of the housing and extending into either of the opposed longitudinal edges. The mechanism also comprises hinge plates supported by the housing for pivoting movement relative to the housing and rings for holding loose-leaf pages, each ring including a first ring member and a second ring member, the first ring member being mounted on a first hinge plate and moveable with the pivoting motion of the first hinge plate relative to the second ring member between a closed position and an open position, in the closed position the two ring members forming a substantially continuous, closed loop for allowing loose-leaf pages retained by the rings to be moved along the rings from one ring member to the other, and in the open position the two ring members forming a discontinuous, open loop for adding or removing loose-leaf pages from the rings.