Abstract: A ring binder adapted to be secured to a base member, the ring binder comprising at least one securing member; a substantially rigid upper structure; a pivotable lower structure supported by the upper structure; a plurality of ring members mounted to the lower structure; and at least one engagement member engageable with the securing member closely adjacent to the base member to secure the ring binder to the base member; wherein the engagement member includes an engagement surface for engaging the securing member, the engagement surface comprising an upper surface of a partially open lower end of the engagement member, and the engagement member comprising a body which is narrower than the partially open lower end.