The two differently sized plates of the book mark consist of a smaller top one (2) and a larger bottom one (1). The smaller plate is slidable up to the top edge of the rigid book spine and can be fastened there by elastic couplers. The book mark has numerous strips which are used as actual marks of the book pages. The large plate pref. contains a pocket or compartment for a writing implement. The small plate is guided by rubber rods, and the book mark has clamping rubber rings.
