Abstract: One or more mounting members are slidably mounted along the strap by threading the strap through a plurality of slits, typically a pair, in each mounting member. The mounting members can be flexible or inflexible, and formed from a variety of materials, such as metals, plastics or a composite material. Each mounting member can additionally include one or more wings, typically a pair, which allows the user to easily slide the mounting member along the strap. A user can grasp a wing to lift an edge of the mounting member away from the strap and then insert one or more sheets between the mounting member and the strap. Once the user releases the wing, the mounting member is urged toward the strap, creating sufficient pressure to hold the inserted sheet in place.