Dual use design for books & files. Forms three wide sections after assembling. Easy to assemble by sliding the plates. Instructions printed on the box. Just fillip the back side down & reposition the front plate for choosing depth between books & files. Indexing stickers on both front & back plate for writing nomenclature Useful at offices to vertically compartmentalize cupboard shelves for neatly organizing & archiving records. Quick way to organize files on office desks.